unilateral acts of states: ninth report on unilateral acts ... · 147 unilateral acts of states...

147

UNILATERAL ACTS OF STATES

[Agenda item 6]

DOCUMENT A/CN.4/569 and Add.1

Ninth report on unilateral acts of States, by Mr. Víctor Rodríguez Cedeño, Special Rapporteur

[Original: Spanish] [6 April 2006]

CONTENTS

Paragraphs Page

Multilateral instruments cited in the present report ........................................................................................................................................ 148

Works cited in the present report .................................................................................................................................................................... 148

IntroductIon ………………. ................................................................................................................................................... 1–9 151

Chapter

I. unIlateral acts of states .......................................................................................................................................... 10–124 152

A. Validity and duration of unilateral acts ............................................................................................................... 10–78 1521. Grounds for invalidity ................................................................................................................................ 11–78 152

(a) Invalidity of a unilateral act on the ground that the representative lacks competence ....................... 18–34 154(i) Article 46 of the 1969 Vienna Convention ................................................................................ 22–30 154(ii) Specific restrictions on authority to express the consent of a State ........................................... 31–34 156

(b) Grounds for invalidity related to the expression of consent ............................................................... 35–66 157(i) Error ........................................................................................................................................... 36–43 157(ii) Fraud .......................................................................................................................................... 44–47 158(iii) Corruption of a representative ................................................................................................... 48–52 159(iv) Coercion ..................................................................................................................................... 53–66 159

a. Coercion of a representative of a State ............................................................................... 54–58 159b. Coercion of a State by the threat or use of force ................................................................ 59–66 160

(c) Invalidity of a unilateral act on the ground that it is contrary to a norm of jus cogens ...................... 67–78 162B. Termination and suspension of unilateral acts and other related concepts ......................................................... 79–124 164

1. Situations arising from the will of the party formulating the unilateral act ............................................... 95–108 1662. Situations arising from circumstances unrelated to the will of the party formulating the unilateral act .... 109–124 169

(a) Situations provided for in the 1969 Vienna Convention .................................................................... 110–119 169(b) Situations not expressly provided for in the 1969 Vienna Convention .............................................. 120–124 171

II. draft guIdIng prIncIples for consIderatIon By the workIng group ........................................................................ 125–161 173

A. Definition of a unilateral act ............................................................................................................................... 126–139 173B. Formulation of a unilateral act ............................................................................................................................ 140–152 174

1. Capacity of a State to formulate a unilateral act ......................................................................................... 140–141 1742. Persons having competence to formulate unilateral acts on behalf of a State ............................................ 142–150 1753. Subsequent confirmation of a unilateral act formulated without authorization .......................................... 151–152 176

C. Basis for the binding nature of unilateral acts .................................................................................................... 153–156 176D. Interpretation of unilateral acts ........................................................................................................................... 157–161 177

Annex. Draft guiding principles ................................................................................................................................................................... 178

148 Documents of the fifty-eighth session

Multilateral instruments cited in the present report

SourceConvention respecting the Free Navigation of the Suez Maritime Canal (Constantinople,

29 October 1888)N. Singh, ed., International Maritime Law

Conventions, vol. 4 (London, Stevens, 1983), p. 2834.

Treaty of Peace between the Allied and Associated Powers and Germany (Treaty of Versailles) (Versailles, 28 June 1919)

British and Foreign State Papers, 1919, vol. CXII (London, HM Stationery Office, 1922), p. 1.

Convention on the Prevention and Punishment of the Crime of Genocide (New York, 9 December 1948)

United Nations, Treaty Series, vol. 78, No. 1021, p. 277.

Vienna Convention on the Law of Treaties (Vienna, 23 May 1969) Ibid., vol. 1155, No. 18232, p. 331.Vienna Convention on Succession of States in respect of Treaties (Vienna, 23 August 1978) Ibid., vol. 1946, No. 33356, p. 3.Convention on the rights of the child (New York, 20 November 1989) Ibid., vol. 1577, No. 27531, p. 3.Inter-American Convention against Corruption (Caracas, 29 March 1996) ILM, vol. 35, No. 5 (September 1996),

p. 724.Criminal Law Convention on Corruption (Strasbourg, 27 January 1999) United Nations, Treaty Series, vol. 2216,

No. 39391, p. 225.Additional Protocol to the Criminal Law Convention on Corruption (Strasbourg, 15 May 2003)

Ibid., vol. 2466, No. 39391, p. 168.

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aspremont lynden, Jean d’“Les travaux de la Commission du droit international relatifs

aux actes unilatéraux des États”, RGDIP, vol. CIX, 2005, pp. 163–189.

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dehaussy, J.“La déclaration égyptienne de 1957 sur le canal de Suez”,

Annuaire français de droit international (Paris), vol. VI, 1960, pp. 169–184.

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of The Hague Academy of International Law, 1971–III. Leiden, Sijthoff, 1972. vol. 134, pp. 333–416.

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fernández tomás, Antonio“El ius cogens y las obligaciones derivadas de normas imperati-

vas: entre el mito y la realidad”, in Ana Salinas de Frías and Marina Vargas Gómez-Urrutia, eds., Soberanía del Estado y derecho internacional: homenaje al profesor Juan Antonio Carrillo Salcedo. Seville, University of Seville, 2005. Vol. I, pp. 619–638.

gaja, Giorgio“Jus cogens beyond the Vienna Convention”, Collected Courses of

The Hague Academy of International Law, 1981–III. The Hague, Martinus Nijhoff, 1982. vol. 172, pp. 271–316.

gómez roBledo, Antonio“Le ius cogens international: sa genèse, sa nature, ses fonctions”,

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El ius cogens internacional: Estudio histórico-crítico. Mexico, Universidad Nacional Autónoma de México, 2003. 195 p.

gonzález vega, Javier A.“El reconocimiento de Belice ante la Corte de Constitucionali-

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guggenheIm, Paul“The validity and the nullity of international legal acts”, Recueil des

cours de l’Académie de droit international de La Haye, 1949–I. Paris, Sirey, 1949. vol. 74, pp. 191–268.

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harasztI, György“Treaties and the fundamental change of circumstances”, Collected

Courses of The Hague Academy of International Law, 1975–III. Leiden, Sijthoff, 1977. vol. 146, pp. 1–93.

hIggIns, RosalynProblems and Process: International Law and How We Use It.

Oxford, Clarendon Press, 1994. 274 p.

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“À propos de la promesse unilatéral”, Mélanges offerts à Paul Reuter―le droit international: unité et diversité. Paris, Pedone, 1981, pp. 327–345.

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koskennIemI, Martti “Report of the Director of Studies of the English-speaking

Section of the Centre”, in Pierre Michel Eisemann and Martti Koskenniemi, eds., State Succession: Codification Tested against the Facts. The Hague, Martinus Nijhoff, 2000, pp. 65–132.

lauterpacht, H., ed.Annual Digest and Reports of Public International Law Cases:

Years 1935–1937. London, Butterworth, 1941.

Annual Digest and Reports of Public International Law Cases: Years 1919–1942. London, Butterworth, 1947.

Annual Digest and Reports of Public International Law Cases: Years 1943–1945. London, Butterworth, 1949.

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1981, vol. 52, 1982, pp. 361–534.

“United Kingdom materials on international law 1982”, BYBIL 1982, vol. 53, pp. 337–570.

“United Kingdom materials on international law 1987”, BYBIL 1987, vol. 58 (1988), pp. 497–650.

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vires treaties): some recent cases”, BYBIL 1978, vol. 49, 1979, pp. 175–199.

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United States has been a Party. Washington, D.C., Government Printing Office, 1898.

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vas tendencias”, Revista de Instituciones Europeas (Madrid), vol. 22, No. 1, 1995, pp. 475–507.

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international public. Athens, Papazissi, 1974.

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September 1971, pp. 617–673.

L’erreur dans les traités. Paris, Librairie Générale de Droit et de Jurisprudence, 1972. 281 p.

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Soviética y de Yugoslavia. Cuenca, Universidad de Castilla- La Mancha, 1996. 100 p.

“Aspectos teóricos y prácticos de la continuidad en la identidad del Estado”, Anuario de Derecho Internacional (Pamplona), vol. XV, 1999, pp. 273–323.

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Revista Española de Derecho Internacional, vol. XV (1962), Nos. 1–2, págs. 97–139.

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international conventions”, Recueil des cours de l’Académie de droit international de La Haye, 1966–II. Leiden, Sijthoff, 1968. vol. 118, pp. 105–208.

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Introduction

1. The International Law Commission considered the eighth report on unilateral acts of States1 at its 2852nd to 2855th meetings, held on 15 and 19–21 July 2005. In accordance with the views expressed by the Working Group on unilateral acts of States and the members of the Commission, as well as the Governments represented in the Sixth Committee of the General Assembly, that report presented a number of examples of unilateral acts of States. While not all of these examples represented uni-lateral acts in the sense with which the Commission is concerned, they served to facilitate progress in the delib-erations on the subject.

2. In the course of the Commission’s discussions, it was once again pointed out that “the diversity of effects and the importance of the setting in which acts occurred made it very difficult to arrive at a ‘theory’ or ‘regime’ of unilat-eral acts”.2 Other members, however, thought that it was possible to establish such a regime,3 albeit with the quali-fications described below.

3. It was also pointed out, during the Commission’s dis-cussions on the topic, that “the practice studied so far, sup-plemented perhaps by further study of other acts ... might provide the basis for a formal definition that nevertheless retained some flexibility”.4 After establishing such a defi-nition, “the Commission should study the capacity and authority of the author of a unilateral act”.5 It was also sug-gested that a “summary of the Commission’s work on the subject, in the form of a declaration accompanied by general or preliminary conclusions and covering all the points which had been accepted by consensus”, should be prepared.6 It was further noted that it was “important not to overlook the need to ensure that States were still free to make political statements at any time without feeling constrained by the possibility of having to accept legal commitments”.7

4. Another view, which had been put forward in the Com-mission a number of times before, was that “unilateral acts were so diverse, and so various and complex in nature, that they could not be codified in the form of draft articles”;8 an “ ‘expository’ study of the topic would thus be the best way to proceed, since the setting in which acts were per-formed was crucial to their identification”.9 Given the diffi-culties that the Commission had encountered in attempting to agree on general rules, it would be better, in the view of some members, to “aim in the direction of guidelines or principles which could help and guide States while provid-ing for greater certainty in the matter”.10

1 Yearbook … 2005, vol. II (Part One), document A/CN.4/557, p. 119.2 Ibid. (Part Two), para. 303, view expressed by Ms. Escarameia

and Mr. Candioti.3 Ibid., views of Messrs. Kamto, Pellet, Candioti and Ms. Xue,

among others.4 Ibid., view of Mr. Fomba.5 Ibid., para. 305, in particular the views of Ms. Escarameia, Mr.

Pellet and Mr. Daoudi.6 Ibid., para. 307, views of Mr. Candioti and Ms. Xue.7 Ibid., para. 309, view of Mr. Pellet.8 Ibid., para. 310, views of Mr. Koskenniemi and Mr. Brownlie.9 Ibid., view of Mr. Brownlie.10 Ibid., para. 314, views of Mr. Candioti and Mr. Pellet, among

others.

5. Another issue that was considered in the course of the Commission’s discussions at its fifty-seventh session and at the meetings of the Working Group on unilateral acts11 was that of the “revocability of a unilateral act”,12 which, it was said, must be taken up if the topic was to be thoroughly studied;13 it is therefore addressed in detail in the present report.

6. The report and the Commission’s deliberations thereon were considered by Member States in the Sixth Commit-tee during the sixtieth session of the General Assembly in 2005. At the meetings held between 24 October and 3 November 2005, government representatives highlighted the difficulty of the topic14 and expressed some concern about the slow progress of the Commission’s work,15 as well as their agreement with the approach taken in the eighth report of the Special Rapporteur;16 they also raised more specific issues in relation to the topic. It was men-tioned that the scope of the topic should be restricted to the obligation a State could assume through a unilateral declaration, the conditions governing its validity17 and its effects on third States, including the corresponding rights of those States. That would obviate the need to examine the enormously complex issue of conduct.18

7. As to how the work on this topic should proceed, some delegations stressed the need to conclude the study in 200619 through the formulation of general conclusions based on the Commission’s previous work,20 albeit with-out losing sight of the specific nature of unilateral acts;

11 Under the chairmanship of Mr. Pellet, the open-ended Working Group held four meetings (11 and 18 May, 1 June and 25 July 2005) (ibid., paras. 327–332).

12 Ibid., para. 315.13 At the request of the members of the Commission, its Chairman at

its fifty-seventh session, Mr. Momtaz, told government representatives in the Sixth Committee that the Commission would welcome comments from Governments on practice regarding the revocation or revision of unilateral acts, their particular circumstances and conditions, the effects of revocation or revision of a unilateral act, and the range of possible reactions from third parties (Official Records of the General Assembly, Sixtieth Session, Sixth Committee, 13th meeting, para. 80).

14 Ibid., 11th meeting, para. 59, statement by Spain; 16th meeting, para. 12, statement by the Russian Federation; 19th meeting, para. 14, statement by the Libyan Arab Jamahiriya; 20th meeting, para. 38, statement by the Bolivarian Republic of Venezuela.

15 Ibid., 11th meeting, para. 46, statement by Morocco; 14th meeting, para. 52, statement by Japan; 15th meeting, para. 10, statement by the Republic of Korea; 16th meeting, para. 52, statement by Guatemala; ibid., para. 72, statement by Kenya.

16 Ibid., 14th meeting, para. 10, statement by Austria; para. 44, statement by New Zealand; para. 52, statement by Japan; ibid., 16th meeting, para. 12, statement by the Russian Federation; para. 21, statement by Poland; para. 46, statement by Chile.

17 Ibid., 11th meeting, para. 59, statement by Spain; para. 74, statement by France.

18 Ibid., para. 59, statement by Spain; para. 74, statement by France; 16th meeting, para. 22, statement by Poland; along the same lines, Chile took the view that it would be better to consolidate the progress achieved with respect to unilateral acts sensu stricto before embarking on a detailed study of conduct (ibid., para. 48).

19 Ibid., 12th meeting , para. 42, statement by Denmark on behalf of the Nordic countries; 16th meeting, para. 35, statement by Portugal.

20 Ibid., 12th meeting, para. 42, statement by Denmark on behalf of the Nordic countries; 13th meeting, para. 106, statement by Argentina; 15th meeting, para. 18, statement by China.


presented in the Special Rapporteur’s reports. Chapter II of the present report deals with topics that have been con-sidered before, from a structural standpoint, in the Com-mission and in the Working Group on unilateral acts of States established in 2004 and 2005 and chaired by Mr. Alain Pellet: the definition of unilateral acts in a way that distinguishes them from other acts which, although appar-ently unilateral, actually constitute a treaty relationship and are therefore subject to the regime established by the 1969 Vienna Convention. In turn, such acts, as manifesta-tions of will in the strict sense, are distinguished from uni-lateral conduct that may produce similar legal effects. On this same subject, reference is made to the addressee or addressees of a unilateral act, although this does not affect the fact that the topic is limited to unilateral acts formu-lated by States. In this regard, the report presents two pro-posals that could form part of the definition of such acts and could determine the scope of the draft guiding prin-ciples; secondly, the report presents proposed language related to the formulation of the act: capacity of the State, persons authorized to act and to enter into legal commit-ments on the State’s behalf in its international relations, and the subsequent confirmation of an act formulated without authorization; thirdly, proposed language is sug-gested in relation to the basis for the binding nature of unilateral acts; and lastly, a draft guiding principle is pre-sented in relation to the interpretation of unilateral acts. A list of all the guiding principles being proposed, including those concerning the invalidity, termination and suspen-sion of unilateral acts, which are discussed in chapter I, is annexed to the present document.

9. The Special Rapporteur proposes that chapter I of this report be considered in plenary session and that chapter II be referred to the Working Group on unilateral acts of States for further consideration, in line with the Working Group’s mandate and in order to expedite the work on the topic at the current session.

that is, without modelling the conclusions too closely on the provisions of the Vienna Convention on the Law of Treaties (hereinafter the 1969 Vienna Convention).21 Other delegations, however, felt that provisions on the law of treaties could be useful as a point of departure and could even be used as a framework, mutatis mutandis.22 One delegation said that the view it had expressed at pre-vious sessions, to the effect that the topic should be set aside, had not changed;23 another said that the difficulty of defining the nature of such acts suggested that they were unamenable to codification or progressive development.24 Other delegations felt that the Commission’s considera-tion of the topic made a positive contribution by identify-ing and clarifying the concept of unilateral acts25 so that ideas or guiding principles could be formulated on the topic;26 that might provide a good foundation to serve as a first step towards possible codification.

8. In response to the concerns expressed by the mem-bers of the Commission, and with a view to facilitating the consideration of the topic, the Special Rapporteur is submitting his ninth report this year. The report is divided into two chapters, the first of which refers to the grounds for invalidity of unilateral acts and the modification and suspension of such acts, together with other related con-cepts. While these issues have arisen in the course of pre-vious years’ deliberations, they have not been formally

21 Ibid., 14th meeting, para. 44, statement by New Zealand.22 Ibid., 15th meeting, para. 10, statement by the Republic of Korea;

16th meeting, para. 54, statement by Guatemala.23 Ibid., 14th meeting, para. 7, statement by the United Kingdom of

Great Britain and Northern Ireland.24 Ibid., 15th meeting, para. 2, statement by the United States of

America.25 Ibid., 16th meeting, para. 46, statement by Chile; para. 54,

statement by Guatemala; 17th meeting, paras. 6 and 10, statement by Cuba; 18th meeting, para. 74, statement by Belarus.

26 Ibid., para. 93, statement by Malaysia.

chapter I

Unilateral acts of States

A. Validity and duration of unilateral acts

10. In this section, the question of the validity and dura-tion of unilateral acts of States is addressed, a topic which, though discussed by the Commission at previous sessions, must be examined in more detail in order to provide the basis for the guiding principles being proposed. Both the Commission and the Sixth Committee have expressed the need to address this topic as thoroughly as possible. With this objective in mind, an attempt will be made to describe the status of the issue, in the literature and in practice, notwithstanding the paucity of precedents.

1. grounds for InvalIdIty

11. The question of the validity of unilateral acts of States has been considered only rarely and tangentially in the legal literature.27 While in the realm of the law of

27 The analysis of this issue draws to a large extent on the conclusions put forward by Torres Cazorla, Los actos unilaterales de los Estados en el derecho internacional contemporáneo, pp. 115–172.

treaties the possible grounds for their invalidity, termina-tion and suspension have been the subject of a huge num-ber of studies and opinions in the literature,28 this has not been the case in the area that is of concern here.29 This is not to say that the topic has not sparked any interest;

28 It should be borne in mind that the 1969 Vienna Convention devotes 31 articles (42–72) and an annex to the invalidity, termination and suspension of the operation of treaties (part V). The Convention’s goal was a laudable one: to lend stability and legal security to treaty relations by limiting the invalidity, termination and suspension of the operation of treaties to a few exceptional circumstances.

29 The view expressed by Pecourt García, “El principio del estoppel en derecho internacional público”, p. 125, may therefore continue to be valid, even though it was expressed before the 1969 Vienna Convention came into being. That view, which could also be applied to unilateral acts of States, is that: “The absence of an organic doctrine and a set of uniform principles governing the validity and invalidity of international legal acts makes it almost impossible to study those concepts in relation to a specific type of act, within a framework of general validity. This means that the question of the validity and invalidity of different types of international acts has to be considered within relatively autonomous conceptual and regulatory frameworks.”


quite the contrary. In fact, almost as soon the Commission began to discuss this topic, government representatives in the Sixth Committee expressed the view that, in the future, the Commission should focus on aspects concern-ing the elaboration and conditions of validity of unilateral acts.30 The Commission itself referred to a working group questions relating to the causes of invalidity; this was “a delicate matter which ... warranted more extensive study, along with the consideration of the question of the condi-tions of validity of a unilateral act”.31

12. Views have been expressed in the literature to the effect that the principle of good faith creates a need to ensure compliance with unilateral commitments. This principle, in turn, reflects the moral obligation to honour one’s promises or, alternatively, the social requirement of ensuring the stability of international relations, and is achieved through the sincerity of the declaring State or the expectation created among third parties that the uni-lateral act will be observed.32 The same body of opinion holds that “thus, with regard to the fundamental require-ment of stability in international relations, unilateral com-mitments offer guarantees of solidity comparable to those of treaty commitments”.33 This assessment also highlights the affinity between these two concepts—unilateral acts and international treaties—and illustrates one of the rea-sons why, in the view of the Special Rapporteur, the study of this topic should consider the provisions of the 1969 Vienna Convention that concern the possible invalidity, termination or suspension of treaties, even though these provisions cannot be transposed wholesale to the realm of unilateral acts, owing to the peculiar characteristics of such acts.34

13. The second major issue that the study will have to address is the near absence of discussion about the con-tingencies that may affect unilateral acts; there is a similar dearth of examples in international practice. Further-more, attempts to extrapolate certain concepts emanating from internal law have given rise to some doubts in the literature, which not even case law, in the few instances in which it has dealt with this subject, has been able to dispel. As Guggenheim correctly pointed out:

[B]y introducing into international law the private law theory relating to defects of consent, one is transposing into the sphere of inter-State relations a doctrine that was originally applied in the sphere of internal law, forgetting that a coherent theory on defects of consent can only

30 The statements made by Austria (Official Records of the General Assembly, Sixtieth Session, Sixth Committee, 13th meeting, para. 10), and Romania (18th meeting, para. 3) illustrate this point particularly well.

31 Yearbook … 2001, vol. II (Part One), document A/CN.4/519, p. 117, para. 4. See also paragraphs 5–6 and 19.

32 Charpentier, “Engagements unilateraux et engagements conventionnels: différences et convergences”, p. 378.

33 Ibid., p. 380.34 Both ideas are highlighted by Akehurst, “The hierarchy of the

sources of international law”, pp. 280–281, where he states that “these acts are so heterogeneous that it is very difficult to generalize about them … in other circumstances unilateral acts are sources of law, or at least of legal rights and obligations … Such acts are similar in their effects to treaties, and probably have the same hierarchical value as treaties; that is to say, a State can, by promise or waiver, lose liberties or rights which it enjoyed under treaties or customary rules, although a subsequent treaty or custom can extinguish the obligations assumed in the promise or revive the rights lost by the waiver”.

be developed through a lengthy accumulation of precedents, which are lacking in international law.35

14. Perhaps as a consequence of this attempt to extrapo-late rules of internal law to the international plane, the lit-erature distinguishes between defects that directly affect the expression of will per se, thereby depriving it of its very essence, and defects that affect the will of the sub-ject, rendering it irregular, but not necessarily eliminating it. Following this line of reasoning, the consequences ini-tially arising from these two situations could also be dif-ferent. Thus, as Venturini points out, “in the first case, the legal act, deprived of one of its constituent parts, must be considered null and void, while in the second case, mere irregularity, which is not manifest, simply means that the subject concerned has the right to challenge the act”.36 Taking a more pragmatic view, Verzijl believed that such distinctions, extrapolated from different legal systems,37 might also be of interest for the purposes of public inter-national law and might be applicable in particular to uni-lateral acts.38

15. This, then, is practically virgin territory, in which references in the literature are scarce—or tend to refer to the law of treaties—and practice is almost non-existent. These are all aspects which, of course, curtail and restrict the scope of the study of the topic, but an attempt will nonetheless be made, to the extent possible, to provide examples to illustrate the concepts discussed.

16. To what extent could the grounds for invalidity pro-vided in the 1969 Vienna Convention be applicable to unilateral acts? It has been said that “when they operate as sources of legal rights and obligations, the common requirements for validity of unilateral acts are essentially the same as for validity of treaties”.39 According to this view, the requirements for validity would therefore be as follows: the unilateral act must have been issued by a person with the capacity to formulate it; its content must be materially possible and not prohibited by a peremp-tory norm of general international law (jus cogens); and the intention expressed by the author of the unilateral act must correspond to the author’s true intention and must

35 Guggenheim, “The validity and the nullity of international legal acts”, p. 197.

36 Venturini, “The scope and legal effects of the behaviour and unilateral acts of States”, p. 420, although this author acknowledges that the distinction between invalidity and voidableness has not been fully accepted in the literature. In fact, in the end the 1969 Vienna Convention made no such distinction.

37 Verzijl, “La validité et la nullité des actes juridiques internationaux”, p. 298, who cites as examples the absolute non-existence of an act, as opposed to invalidity as such; invalidity and voidableness; absolute invalidity and relative invalidity; invalidity that can be declared by the courts proprio motu versus invalidity that must be recognized because the parties so decide; total invalidity and partial invalidity; invalidity that can be remedied versus invalidity that cannot; and invalidity with ex nunc and ex tunc effects.

38 Ibid., p. 306.39 Degan, “Unilateral act as a source of particular international

law”, p. 187. Practically the same view was upheld by Skubiszewski, “Unilateral acts of States”, p. 230, where the author states the following: “Any unilateral act must express the true intention of its author. Hence unilateral acts obtained by error, fraud or corruption of a State representative are voidable, and those which result from coercion (whether of the State representative or the State itself) are null and void. In this respect there exists much analogy between invalidity of treaties and unilateral acts.”


not be affected by defects or invalidating factors. As to the form that unilateral acts should take, it is assumed that there is considerable freedom here; however, as the same body of opinion points out, there are some unilateral acts for which formal notification is required in order to publicize them in a timely fashion and give them legal security40 (as is the case, for example, in the law of the sea with respect to the delineation of baselines and the delimitation of the respective zones).41 As stated in pre-vious reports and again at the beginning of the present report, unilateral acts of this kind are linked to a treaty regime and are therefore governed by the specific treaty regime in which they are subsumed.

17. The grounds for invalidity that will be discussed here will be divided into the following three categories: (a) invalidity of a unilateral act on the ground that the rep-resentative lacks competence; (b) grounds for invalidity related to the expression of consent; and (c) invalidity of a unilateral act on the ground that it is contrary to a norm of jus cogens.

(a) Invalidity of a unilateral act on the ground that the representative lacks competence

18. As will be discussed in detail in chapter II, from international practice it can be inferred that, in addition to persons representing the State at the highest level, there are others who, by virtue of their functions and in a spe-cific context, can act and enter into commitments on the State’s behalf in its international relations, by formulating legally binding unilateral acts.

19. In accordance with the majority of legal experts and international practice, it may be assumed that those persons that represent the State at the highest level and therefore have the capacity to express the consent of the State in a treaty context also have the capacity to bind their State by means of unilateral acts. This is an extrapo-lation—with all the risks that analogies entail—of arti-cle 7, paragraph 2 (a), of the 1969 Vienna Convention. However, the international plane presents many complex-ities in this regard, of which one in particular will be men-tioned: the possibility that other persons, some of whom are referred to in the article in question (diplomatic agents or representatives to an international conference) and some of whom are not (persons who produce appropriate full powers), may have some capacity to bind the State they represent. This question was discussed previously

40 ICJ took a very strict approach in this respect in its recent decision in the dispute between the Democratic Republic of the Congo and Rwanda (Armed Activities on the Territory of the Congo (New Application: 2002) (Democratic Republic of the Congo v. Rwanda), Jurisdiction and Admissibility, Judgment, I.C.J. Reports 2006, p. 25, para. 41), in which, referring specifically to the withdrawal of reservations, it stated the following: “Thus a clear distinction has to be drawn between a decision to withdraw a reservation to a treaty taken within a State’s domestic legal order and the implementation of that decision by the competent national authorities within the international legal order, which can be effected only by notification of withdrawal of the reservation to the other States parties to the treaty in question.”

41 This is because of the unique nature of such acts, which are governed by treaties regarding the law of the sea. In this respect, as stated by Ruiloba García, Circunstancias especiales y equidad en la delimitación de los espacios marítimos, p. 34: “Maritime delimitation is heterogeneous in nature, insofar as each case of delimitation has its own specific characteristics that make it unique and unrepeatable, like a snowflake.”

with regard to persons qualified to act and to enter into commitments on behalf of the State.

20. What would happen if a State representative were to overstep his or her authority? This question is more directly related to the approach widely taken in internal law. The respective constitutional texts tend to provide a fairly exhaustive list of which national bodies can partici-pate—and how—in expressing the consent of the State to be bound where international treaties are concerned, but not where unilateral acts are concerned.42

21. The 1969 Vienna Convention’s provisions on the possible factors affecting the competence of the State rep-resentative to bind the State by means of treaties reflect a cautious approach based on the premise that such provi-sions are in the nature of exceptions and, therefore, on the principle of preserving and maintaining the treaty rela-tionship. The Special Rapporteur believes that the same principle must be given primacy where unilateral acts are concerned; failure to do so would generate distrust in international relations and, as a consequence, jeopardize the use of unilateral acts as a way for States to act and commit themselves at that level. Furthermore, the situa-tion of uncertainty and failure to honour promises which invocation of one of the grounds for invalidity currently being discussed could create would tip the scales in favour of validating, where possible, a unilateral act that has this defect. In order to clarify this issue, the Special Rappor-teur believes it would be very useful to discuss again, at least briefly, two of the provisions of part V of the Con-vention, in order to verify whether or not these provisions could be applicable to the subject that is of concern.

(i) Article 46 of the 1969 Vienna Convention

22. As is well known, article 46, paragraph 1, entitled “Provisions of internal law regarding competence to con-clude treaties”, states the following: “A State may not invoke the fact that its consent to be bound by a treaty has been expressed in violation of a provision of its inter-nal law regarding competence to conclude treaties as invalidating its consent unless that violation was manifest

42 In this sense, the Special Rapporteur fully shares the view expressed by Remiro Brotóns to the effect that:

“[T]he constitutional enshrinement of parliamentary participation in treaties reflects a static vision of the ways in which international rules and obligations are produced. Treaties are by no means the only way. Autonomous unilateral acts of international relevance (recognition, promise, protest, reprisal) come to mind ... This is an area in which the Chambers—and sometimes even the Government, as a collegiate body—does not participate, even though it is illogical that something may be promised without the Chambers, but may be undertaken only with them by means of a treaty. In order to clarify this grey area a new vision is needed that offers solutions other than participation by the Chambers, in line with the fluidity of these commitments and the way they are incorporated into positive law. At the moment, only a few State systems have dared to venture into this territory, and the Spanish system is not one of them. The Constitutions of Denmark (art. 19.3) and Sweden (chap. X, arts. 2, 6–8; XIII, art. 2) can be cited as examples of an innovative model for full participation—but not strict control—by the Chambers in the most significant foreign policy decisions, whatever form they may take. These Constitutions provide for the establishment of smaller representative bodies, ready to meet at a moment’s notice, which gather confidential information on developments in international relations and are consulted by the Government before important decisions are adopted.”

(Remiro Brotóns, Derecho Internacional Público, p. 116)


and concerned a rule of its internal law of fundamental importance.”43

23. The negative wording of this provision reflects the fact that it concerns an exception; in principle, no State may invoke a provision of its internal law regarding com-petence to conclude treaties with a view to declaring an agreement null and void. If this is true for treaties, the question arises as to whether this solution can be extrapo-lated to unilateral acts. With regard to the view expressed by PCIJ in 1932 in the case of the Treatment of Pol-ish Nationals and Other Persons of Polish Origin in the Danzig Territory,44 it should be pointed out that the 1969 Vienna Convention adopted a more nuanced position in this respect. This may be because the Commission, in view of historical precedents, took the realistic view45 that some room should be left for certain particularly drastic cases,46

43 The explanation of what is understood by manifest violation is found in paragraph 2 of the same article, which states that a “violation is manifest if it would be objectively evident to any State conducting itself in the matter in accordance with normal practice and in good faith”. In this respect, see Meron, “Article 46 of the Vienna Convention on the Law of Treaties (ultra vires treaties): some recent cases”.

44 Treatment of Polish Nationals and Other Persons of Polish Origin in the Danzig Territory, Advisory Opinion, 1932, P.C.I.J., Series A/B, No. 44, p. 24, which reads as follows:

“It should however be observed that, while on the one hand, according to generally accepted principles, a State cannot rely, as against another State, on the provisions of the latter’s Constitution, but only on international law and international obligations duly accepted, on the other hand and conversely, a State cannot adduce as against another State its own Constitution with a view to evading obligations incumbent upon it under international law or treaties in force. Applying these principles to the present case, it results that the question of the treatment of Polish nationals or other persons of Polish origin or speech must be settled exclusively on the bases of the rules of international law and the treaty provisions in force between Poland and Danzig.”45 However, see Yearbook … 1966, vol. II, document A/6309/Rev.1,

p. 241, para. (7), which refers to this question, pointing out that:“State practice furnishes examples of claims that treaties were

invalid on constitutional grounds, but in none of them was that claim admitted by the other party to the dispute. Moreover, in three instances—the admission of Luxembourg to the League, the Politis incident and the membership of Argentina—the League of Nations seems to have acted upon the principle that a consent given on the international plane by an ostensibly competent State agent is not invalidated by the subsequent disclosure that the agent lacked constitutional authority to commit his State.”46 A historic example of a unilateral act that was contrary to

important constitutional rules, making its performance impossible, was the case of George Croft (Portugal v. United Kingdom), which was resolved on 7 February 1856:

“If at any time the Portuguese Government, or its legal representative, had given to the British Government, in its usual forms of international intercourse, a promise that Mr. Croft should be assisted in obtaining the satisfaction of his claims, or that he was to be held harmless in regard thereto, that there could be no doubt that a perfectly valid title to satisfaction or indemnification from the Portuguese state would arise therefrom, since those are constitutional forms recognized by the law of nations, in which the international obligations of one country toward another are contracted. But the same can not be asserted of a case where nothing else is apparent but an order which the government issued to its own authorities in favour of a foreign subject, without any promise having been previously made to that subject’s government. If in such a case the order meets with constitutional obstacles, which render its execution impossible, no claim founded on international law can be made upon the government for damages on account of its order not having been carried into execution.”

(Moore, History and Digest of the International Arbitrations to which the United States has been a Party, pp. 4982–4983). See also Coussirat-Coustère and Eisemann, Repertory of International Arbitral Jurisprudence, p. 46.

such as those described in the articles to which reference is being made in this section. In principle, this is based on a concern for preserving the validity of treaties and consid-ering the situations referred to below as exceptions.

24. It is necessary to discuss whether it is possible to invoke, as a ground for invalidating a unilateral act, the fact that the act was formulated in manifest violation of a provision of internal law that is of fundamental impor-tance and concerns competence to conclude treaties. As pointed out above, the main problem here is that consti-tutional texts tend to specify the mechanisms and bodies that can participate in expressing the consent of the State where international treaties are concerned, but not where unilateral acts are concerned.

25. Article 46 of the 1969 Vienna Convention lays down three conditions for invoking the invalidity of a treaty: (a) the violation invoked must concern a rule of internal law of fundamental importance, meaning the Constitution and laws that have constitutional force and are in effect at the time (for this requirement to apply to unilateral acts, these laws would have to be in force both when the unilateral act in question was formulated and when the alleged invalidity is claimed); (b) the rule in question must concern compe-tence to conclude treaties, a phrase which, if interpreted in its strictest sense, could, in the view of the Special Rappor-teur, be extrapolated to unilateral acts, with the qualifications discussed below; and (c) the violation of internal law must be manifest, meaning that it must be objectively evident to any State dealing with the matter normally and in good faith.47

26. In his second report on unilateral acts of States, the Special Rapporteur proposed an article which, following fairly closely the provisions of the 1969 Vienna Conven-tion, set out in seven paragraphs the possible grounds for invalidating a unilateral act. The draft article read as follows:

Article 7. Invalidity of unilateral acts

A State may invoke the invalidity of a unilateral act:

...

(g) If the expression of a State’s consent to be bound by a unilat-eral act has been in clear violation of a norm of fundamental importance to its domestic law.48

27. This draft article was less restrictive than article 46 of the 1969 Vienna Convention, since it referred to a clear violation of a norm of fundamental importance, but did not specifically indicate that the norm should concern the competence to express consent (in this instance with respect to unilateral acts).49

47 See Elias, “Problems concerning the validity of treaties”, pp. 357–358; see also Yearbook ... 1966 (footnote 45 above), p. 242, para. (11). The Commission concluded that it would be impracticable and inadvisable to try to specify in advance the cases in which a violation of internal law may be held to be “manifest”, since the question must depend to a large extent on the particular circumstances of each case.

48 Yearbook … 1999, vol. II (Part One), document A/CN.4/500 and Add.1, p. 207, para. 109.

49 During discussions at the fifty-first session of the Commission in 1999, members expressed divergent views with respect to this article; some members maintained that this norm should follow article 46 of the 1969 Vienna Convention more closely, while others believed that the provision should reflect the flexibility inherent in unilateral acts (ibid., vol. II (Part Two)), p. 136, para. 559.


28. The corresponding draft article presented in the third report on unilateral acts of States the following year (art. 5 (h)), was even more laconic, and established the follow-ing as grounds for invalidity: “If the unilateral act as for-mulated conflicts with a norm of fundamental importance to the domestic law of the State formulating it.”50 This wording elicited various reactions from the members of the Commission, as set out in the report on the work of its fifty-second session in 2000:

In the view of some members, the subparagraph, as drafted, might be interpreted as giving priority to domestic law over commitments under international law, and this would be unacceptable. Some members also wondered whether the subparagraph might not lend itself to a situation whereby a State would utilize the provisions of its own national law to evade international obligations which it had assumed by a valid unilat-eral act.51

Furthermore, one of the suggestions made in the course of these discussions was that this subparagraph should bring out the fact that, at the time the act was formulated, there had been a breach of an internal norm of fundamental importance to domestic or constitutional law “concern-ing the capacity to assume international obligations or to formulate legal acts at the international level”.52 If that proposal was not accepted, the very general nature of the draft article might suggest that any violation of a norm of domestic law, albeit one of substantial importance, could cause the unilateral act to be declared invalid, with the risks that that entailed.

29. The inclination of the Special Rapporteur, which closely mirrors the arguments raised in Vienna and reflected in the 1969 Vienna Convention, is to take a restrictive approach to the grounds for invalidity in general and the one mentioned in the preceding paragraph in particular. In the interest of legal security, State repre-sentatives must be cautious in undertaking international commitments and, by extension, unilateral acts. Similarly, there is always the possibility of subsequently confirming the act in question. This solution not only avoids the dras-tic step of declaring an act invalid, but also puts the State in a much better position with respect to the undertaking of commitments and the honouring of promises.53

50 Yearbook … 2000, vol. II (Part One), document A/CN.4/505, p. 264, para. 167.

51 Ibid., vol. II (Part Two), p. 98, para. 602.52 Ibid., para. 603.53 An interesting case in this regard was resolved by the

Constitutional Court of Guatemala in its ruling of 3 November 1992, which affirmed the validity of a series of actions undertaken by the President of the Republic, Jorge Serrano Elías, by virtue of which he had recognized Belize and established diplomatic relations with it. The historic confrontation between Belize and Guatemala gave rise to arti-cle 19, paragraph 1, of the transitory provisions of the 1985 Constitution of Guatemala, which states:

“The Executive is empowered to take steps aimed at resolving the status of Guatemala’s rights with respect to Belize, in line with its national interests. Any final agreement must be submitted by the Congress of the Republic to the popular consultation procedure established under article 173 of the Constitution.” The issue at stake was whether the recognition of Belize by

Guatemala should be considered a “final agreement” and, if so, whether the manifestations and consequences of the President’s actions should be considered invalid. The majority opinion of the judges who participated in the issuing of this ruling of the Constitutional Court was that the act of recognition was a result of the changes this dispute had undergone as a result of the independence of this territory from the United Kingdom, without it being regarded as a final step, in the sense and with the effects implied by the Constitution. Nevertheless, a different position was taken

30. In accordance with the foregoing, the following draft guiding principle on compliance of the unilateral act with the domestic legal order could be formulated:

“Invalidity of a unilateral act that conflicts with a norm of fundamental importance to the domestic law of the State formulating it

“A State that has formulated a unilateral act may not invoke as grounds for invalidity the fact that the act con-flicts with its domestic law, unless it conflicts with a norm of fundamental importance to its domestic law and the contradiction is manifest.”

(ii) Specific restrictions on authority to express the con-sent of a State

31. Article 47 of the 1969 Vienna Convention, enti-tled “Specific restrictions on authority to express the consent of a State”, is directly related to the topic of this discussion. According to that article:

If the authority of a representative to express the consent of a State to be bound by a particular treaty has been made subject to a specific restriction, his omission to observe that restriction may not be invoked as invalidating the consent expressed by him unless the restriction was notified to the other negotiating States prior to his expressing such consent.

32. This rule is even more restrictive than article 46, discussed above. Nahlik’s firm opinion in relation to both rules is that “practical cases in which either of the two articles concerned could be invoked will be extremely rare”.54 However, the application of the concept con-tained in article 47 cannot be extrapolated in toto to uni-lateral acts, given the aforementioned special features of these acts, which stem, principally, from the very means by which they are formulated. In contrast with inter-national treaties, wherein State representatives would be able to inform the representatives of other States of any restrictions on the expression of consent, the very essence of a unilateral act, in respect of which there are no other negotiating parties, renders the aforementioned provision meaningless. In fact, this was not among the grounds for invalidity mentioned in the second and

in the “reasoned dissent” of the President of the Court and two judges; following González Vega (“El reconocimiento de Belice ante la Corte de Constitucionalidad de Guatemala: la sentencia de 3 de noviembre de 1992”, p. 580), who presented the same solution maintained by this minority, in the absence of participation by the Congress of the Republic and the people, the act of recognizing Belize did not represent the decision of the State, and therefore could produce no legal effect or be executed. That author therefore concluded the following:

“Here is the clear consequence upheld by the minority in the Constitutional Court: the invalidity of the act of recognition, and implicitly its revocability, since it was issued by an organ without competence under the Guatemalan Constitution.”

(Ibid., p. 584)There are perhaps many factors that led the Court to adopt its

decision, such as the changes on the international scene, and the desire to avoid casting doubt on the Guatemalan position because of an act carried out by its highest representative. In this regard, see González Vega, loc. cit. Another case similar to the previous one was considered in the eighth report on unilateral acts of States (Yearbook … 2005 (footnote 1 above), pp. 123–125, paras. 13–35) and concerned a 1952 note from the Minister for Foreign Affairs of Colombia on the Los Monjes group of islands.

54 Nahlik, “The grounds of invalidity and termination of treaties”, p. 741.


third reports on unilateral acts of States,55 although those reports did refer to one of the initial provisions of the draft articles: the one concerning the possibility of sub-sequent confirmation of a unilateral act, which was dis-cussed earlier.

33. Two aspects were added to the similar provision in the 1969 Vienna Convention: the reference to the act of committing the State on the international plane (an essen-tial aspect of unilateral acts, even though it could also be considered applicable to treaty law), and the provision on compulsory confirmation.

34. On this basis, the following draft guiding princi-ple is presented, on the understanding that it might not be necessary, as another guiding principle on the con-firmation or validation of a unilateral act has already been formulated and has been submitted for the con-sideration of the Working Group on unilateral acts of States:

“Invalidity of an act formulated by a person not qualified to do so

“A unilateral act formulated by a person not author-ized or qualified to do so may be declared invalid, without prejudice to the possibility that the State from which the act was issued may confirm it in accordance with guiding principle 4.”

(b) Grounds for invalidity related to the expression of consent

35. All the possible grounds for invalidity studied in this section share the common denominator of flawed consent to be bound by a unilateral act. The 1969 Vienna Convention again serves as a reference point. Three of these grounds (error, fraud and coercion) are rooted in the Roman-law tradition and were introduced into the Con-vention for basically two reasons: because they served as a type of safety valve in case any of these circum-stances arose, although this rarely happens, and because their inclusion would obviate any argument that the Con-vention’s provisions on grounds for invalidity were not exhaustive, thereby preventing States from seeking other possible grounds for invalidity. Each of them will now be looked at.

(i) Error

36. In its report to the General Assembly at its eight-eenth session in 1966, which contained the draft articles on the law of treaties and commentaries thereon, the Commission stressed that “the instances in which errors of substance have been invoked as affecting the essen-tial validity of a treaty have not been frequent. Almost all the recorded instances concern geographical errors, and most of them concern errors in maps”.56 If this is true with respect to treaties, it should also be true with respect to unilateral acts.

55 Yearbook … 1999 and Yearbook … 2000 (see footnotes 48 and 50 above).

56 Yearbook ... 1966 (see footnote 45 above), p. 243, para. (1) of the commentary to article 45.

37. There have been very few cases, in either interna-tional practice or existing case law, in which error has been cited as a ground justifying a declaration of invalid-ity. There are, however, some illustrative cases. For exam-ple, in the Legal Status of Eastern Greenland case, Judge Anzilotti, in his dissenting opinion, stated that:

A question of a totally different kind is whether the declaration of the Norwegian Minister for Foreign Affairs was vitiated, owing to a mistake on a material point, i.e. because it was made in ignorance of the fact that the extension of Danish sovereignty would involve a cor-responding extension of the monopoly and of the régime of exclusion.

...

My own opinion is that there was no mistake at all, and that the Danish Government’s silence on the so-called monopoly question, and the absence of any observation or reservation in regard to it in M. Ihlen’s reply, are easily accounted for by the character of this over-ture, which was made with a future settlement in view. But even accept-ing, for a moment, the supposition that M. Ihlen was mistaken as to the results which might ensue from an extension of Danish sovereignty, it must be admitted that this mistake was not such as to entail the nullity of the agreement. If a mistake is pleaded it must be of an excusable character; and one can scarcely believe that a government could be ignorant of the legitimate consequences following upon an extension of sovereignty*; I would add that, of all the governments in the world, that of Norway was the least likely to be ignorant of the Danish meth-ods of administration in Greenland, or of the part played therein by the monopoly system and the régime of exclusion.57

38. It is generally recognized that, in order to vitiate the consent of a State in a treaty, an error must relate to an issue that forms an essential basis of the State’s consent to be bound by the treaty; the Special Rapporteur believes that this same solution should be applied, mutatis mutan-dis, to unilateral acts of States.58

39. In his second report on unilateral acts of States, the Special Rapporteur proposed a provision that was almost identical to the provision of the 1969 Vienna Convention concerning error (art. 48), although it condensed into one paragraph the basic features that such an error must have, as follows:


(a) If the expression of the State’s consent to formulate the act was based on an error of fact or a situation which was assumed by that State to exist at the time when the act was formulated and formed an essential basis of its consent to be bound by the act. The foregoing shall not apply if the State contributed by its own conduct to the error or if the circum-stances were such as to put that State on notice of a possible error.59

40. Various opinions were expressed on the matter within the Commission. For example, it was said that the wording should be further disassociated from the 1969 Vienna Convention, taking into account the difference between unilateral acts and international treaties;60 it was also suggested that the word “consent” should not be used “because of its treaty connotations”.61 This suggestion

57 Legal Status of Eastern Greenland, Judgment, 1933, P.C.I.J., Series A/B, No. 53, p. 92.

58 As highlighted by Oraison, L’erreur dans les traités, p. 41.59 Yearbook … 1999 (see footnote 48 above), p. 207, para. 109,

art. 7.60 The view was expressed that an error of fact committed by a State

when formulating a declaration should be easier to correct than an error related to an international treaty, given the flexibility and speed with which unilateral acts are usually formulated, as opposed to treaties (ibid., vol. II (Part Two), p. 135, para. 555).

61 Yearbook … 2000, vol. II (Part Two), p. 97, para. 593.


was retained in the third report on unilateral acts of States, which kept the entire draft article unchanged except the opening phrase, which read, “If the act was formulated on the basis”,62 instead of the phrasing previously used (“If the expression of the State’s consent to formulate the act was based”).

41. In reality, the Special Rapporteur believes that error, as a circumstance that can lead to the invalidity of a uni-lateral act, must have been an essential determinant of the State’s conduct. Moreover, the requirement of good faith—directly linked to the fact that the State claiming invalidity must not have contributed to the error by its own conduct—serves to prevent possible conduct whose ultimate aim is to release the State in question from com-mitments undertaken in the international sphere.

42. Error must be claimed by the State that formulated the unilateral act and committed the error, although a hypothetical situation could arise in which a third State that is the beneficiary of the unilateral act discovers, in view of the circumstances of the case, that there has been an error and so informs the author State. In an even more unusual case, it could also transpire that the error was caused by the fraudulent conduct of a third party, which would give rise to two possible causes of invalidity and would invalidate the unilateral act in question, unless the circumstances of the case and the will of the State having formulated the act make it advisable that the act should remain in effect, through its confirmation.

43. Draft guiding principle 7, paragraph 1, which is repro-duced below, addresses this potential cause of invalidity; the remaining paragraphs on grounds for invalidity will be cited further on, after the commentary relating to each of them:

“Invalidity of unilateral acts

“1. (a) A State that is the author of a unilateral act may not invoke error as grounds for declaring the act invalid, unless the act was formulated on the basis of an error of fact or a situation that was assumed by the State to exist at the time when the act was formulated and that fact or that situation formed an essential basis of its consent to be bound by the unilateral act;

“(b) The foregoing shall not apply if the author State contributed by its own conduct to the error or if the cir-cumstances were such as to put that State on notice of the possibility of such an error.”63

(ii) Fraud

44. In accordance with article 49 of the 1969 Vienna Convention: “If a State has been induced to conclude a treaty by the fraudulent conduct of another negotiating State, the State may invoke the fraud as invalidating its consent to be bound by the treaty.” Whether this cause

62 Ibid., vol. II (Part One) (see footnote 50 above), p. 263, para. 167.63 To allow for the invocation of error by States other than the State

that formulated the unilateral act, the following wording is submitted to the Commission for its consideration:

“Error may be invoked as grounds for declaring a unilateral act invalid if the act was formulated on the basis of an error of fact or a situation that was assumed by the State to exist at the time when the act was formulated and that fact or that situation formed an essential basis of its consent to be bound by the unilateral act.”

of invalidity of an international treaty could be applied, mutatis mutandis, to a unilateral act should therefore be considered. In Sicault’s view, both fraud64 and error are causes of invalidity that are fully applicable to unilateral acts. The reference to both causes is probably due to the fine line between them, which has been illustrated on sev-eral occasions in the legal literature.65

45. If this cause of invalidity is accepted in the case of unilateral acts, it should be subject to the same conditions required in order for fraud to be taken into consideration in a treaty context. Remiro Brotóns highlights three el-ements of the conduct of a third party that must be present in order for the conduct to be qualified as fraudulent and for the act whose formulation was induced to be declared invalid: (a) a material element, referred to as fraudulent conduct, which, in the Commission’s view, encompasses “any false statements, misrepresentations or other deceit-ful proceedings”;66 (b) a psychological element, meaning the will or intention to mislead (in the context of unilat-eral acts, the will to induce the State formulating the act to implement the provisions thereof, regardless of their nature); and (c) a result, achieved by fraudulent means. In this connection, it is said that the fraud must be of an essential nature.67

46. With regard to unilateral acts, the proposal submit-ted to the Commission in the second report of the Special Rapporteur appears in what was then draft article 7 (b), according to which, “If a State has been induced to for-mulate an act by the fraudulent conduct of another State”, it may invoke the invalidity of the act.68 The report went on to state that: “Fraud can even occur through omission, as when a State which has knowledge of certain realities does not convey it, thus inducing another State to formu-late a legal act.”69 However, this last point elicited various criticisms from several members of the Commission, who took the view that that interpretation “might encroach on certain accepted ways whereby States led their foreign policy and convinced other States to join in that policy”.70 Interpretation will have to be relied on to draw a distinc-tion between situations in which fraud is present and those in which it is not.

47. The same draft guiding principle on grounds for invalidity contains a second paragraph, which reads as follows:

“2. Fraud may be invoked as grounds for declaring a unilateral act invalid if the author State was induced to

64 Sicault, “Du caractère obligatoire des engagements unilatéraux en droit international public”, p. 667: “It must be admitted that if the author of a unilateral undertaking has been induced to enter into that undertaking by the fraudulent conduct of another subject of public international law, it may invoke the fraud as invalidating its consent to be bound by the undertaking.”

65 See Oraison, “Le dol dans la conclusion des traités”, p. 622.66 Yearbook … 1966 (see footnote 45 above), p. 245, para. (3) of the

commentary to article 46.67 Remiro Brotóns, op. cit., p. 435.68 Yearbook … 1999 (see footnote 48 above), p. 207, para. 109, and

draft article 5 (b), of the third report, Yearbook … 2000 (see footnote 50 above), p. 264, para. 167, which is identical.

69 Yearbook … 1999 (see footnote 48 above), p. 209, para. 136.70 Ibid., vol. II (Part Two), p. 135, para. 555.


formulate the act by the fraudulent conduct of another State.”

(iii) Corruption of a representative

48. Although this cause of invalidity was a late addition to the draft articles that became the 1969 Vienna Conven-tion, because it was originally thought to be subsumed under the concept of fraud, a decision was taken to include it in the text as article 50, which reads as follows: “If the expression of a State’s consent to be bound by a treaty has been procured through the corruption of its representative directly or indirectly by another negotiating State, the State may invoke such corruption as invalidating its consent to be bound by the treaty.” Of course, the strength of the term “corruption” makes it necessary to define the concept pre-cisely. The customary decorations and hospitality which are a normal part of diplomatic practice would not be regarded as corruption; something extra would be required.71 The lack of precedents may be due to the fact that States are reluctant to admit that their representatives are responsible for giving this defective form of consent.72

49. The role played by this potential cause of inva-lidity in the context of unilateral acts could be almost identical to the role it plays in the treaty context; an analysis of the way in which that cause was described in the second report on unilateral acts of States revealed certain limitations, which were subsequently removed in the third report. The original draft text (art. 7 (c)) read as follows:


...

(c) If the expression of a State’s consent to be bound by a unilat-eral act has been procured through the corruption of its representative directly or indirectly by another State.73

50. The phrase “If the expression of a State’s consent to be bound” limits the scope of application of the draft article, which was further refined in the third report on unilateral acts of States to read as follows: “If the act has been formulated as a result of corruption of the per-son formulating it, through direct or indirect action by another State.”74 The first part of the provision contains the amendment; it now reads “If the act has been formu-lated”, and the term “representative” has been replaced with the phrase “person formulating it”, which, while more general, introduces a greater degree of uncertainty.

51. A cause of this nature is certainly necessary and useful, given that the realities of international rela-tions may give rise to such acts. Some members of the Commission expressed their support for its inclusion

71 For a definition of the term “corruption” see Yearbook ... 1966 (footnote 45 above), p. 245, para. (4) of the commentary to article 47, which specifies that “only acts calculated to exercise a substantial influence on the disposition of the representative to conclude the treaty may be invoked as invalidating the expression of consent which he has purported to give on behalf of his State”, not “a small courtesy or favour” that may be shown to him in connection with the conclusion of the treaty.

72 As Sinclair states in The Vienna Convention on the Law of Treaties, p. 175: “There is no doubt a practical safeguard in that States will be reluctant to admit that their own representatives have been corrupted.”

73 Yearbook … 1999 (see footnote 48 above), p. 207, para. 109.74 Yearbook … 2000 (see footnote 50 above), p. 264, para. 167.

because of the need to combat that situation univer-sally, as underlined by the Inter-American Convention against Corruption, and the Criminal Law Convention on Corruption, adopted by the Council of Europe, and its Additional Protocol. Another interesting devel-opment, described in the Commission’s report to the General Assembly on the work of its fifty-second ses-sion in 2000, was the question raised as to “whether it was necessary to narrow down the possibility of cor-ruption to ‘direct or indirect action by another State’ ”. This point highlighted something that has become an undeniable fact of international life today, given the enormous power that certain entities can acquire; namely, that: “The possibility could not be ruled out that the person formulating the unilateral act might be corrupted by another person or by an enterprise.”75

52. In line with the foregoing, paragraph 3 of the draft guiding principle would read as follows:

“3. Corruption of the representative of the State may be invoked as grounds for declaring a unilateral act invalid if the act was formulated owing to the corruption of the person formulating it.”

(iv) Coercion

53. Together with error and fraud, and bearing in mind the nuances discussed below, coercion is the third cause of invalidity provided for in the 1969 Vienna Conven-tion, and one which finds its origin in the strong tradition of Roman law. The Convention covers coercion of two types: coercion of a representative of a State (art. 51) and coercion of the State itself by the threat or use of force (art. 52). Both types seem to be fully applicable to unilat-eral acts of States.

a. Coercion of a representative of a State

54. In practice, there have been a number of cases in which coercion of a State representative, sometimes to the point where the latter fears for his or her life, has led to the conclusion of agreements and even to the formulation of acts which, without that coercion, would not have exist-ed.76 The notion of coercion, which must be used against a representative (as an individual, not as an organ of the State), encompasses a wide variety of situations, includ-ing, as pointed out by the Commission in its commentary on the draft articles, “any form of constraint or threat”77 affecting the representative’s physical integrity, freedom, career, property or social or family situation.

75 Ibid., vol. II (Part Two), p. 97, para. 594.76 An interesting example can be found in Remiro Brotóns, op.

cit., p. 438: “Once there, having been taken prisoner on 20 April, he [Ferdinand VII] was threatened with the death penalty for having committed high treason against his father, Charles IV, unless he abdicated, which he did on 6 May. One day earlier, in exchange for monetary compensation, Charles IV had ceded his rights to Napoleon, who, in turn, ceded them to his brother Joseph. Those acts were considered invalid on grounds of fraud and violence by the Cádiz Cortes, which subsequently, in 1811, issued a Decree proclaiming the invalidity of any undertaking made by Ferdinand VII while he was imprisoned at Valencey.”

77 Yearbook … 1963, vol. II, document A/5509, p. 197, para. (2) of the commentary to article 35.


55. In the treaty context, one of the principal character-istics distinguishing coercion from corruption is the fact that the former can be employed by anyone, while the latter is only recognized when it is employed by another negotiating State. With regard to unilateral acts, there is value in incorporating both these elements into the defini-tion of the two aforementioned concepts, since there is nothing to preclude the possibility that corruption may be imputable to individuals or entities which are not States as such, but whose ability to exert pressure may corrupt a representative by inducing him or her to undertake a com-mitment which, in the absence of such corruption, would not have been made.

56. It might be unwise to impose excessive restrictions on this cause of invalidity, such as those that were appar-ent in draft article 7 of the second report on unilateral acts of States, which provided that the invalidity of a unilateral act could be invoked “[i]f the expression of a State’s con-sent to be bound by a unilateral act has been procured by the coercion of its representative through acts or threats directed against him”.78 The expression “directed against him” could be interpreted to mean that such coercion—in Spanish, “coacción” is a more appropriate term than “coerción”, since the latter implies an element of physi-cal force that is not necessarily present—could also be directed against the representative’s immediate personal interests (such as his or her property or family) and thereby produce the desired result.

57. The following year’s proposal included a number of amendments similar to those discussed in relation to corruption, but the rest of the aforementioned elements were generally retained; the proposal read as follows: “If the act has been formulated as a result of coercion of the person formulating it, through acts or threats directed against him.”79 The particular conclusiveness of this cause of invalidity was noted by the Commission, which took the view that

the use of coercion on the person formulating the act was a special case, since, in those circumstances, the person involved was not expressing the will of the State he was supposed to represent, but that of the State using coercion. Without a will, there was no legal act and, if there was no act, there was nothing to be invalidated. Whereas other subpara-graphs were cases of negotium nullum, the subparagraph in question was a case of non negotium.80

Accordingly, this situation gives rise to initial invalidity, since the act in question never existed, having been inva-lid from the outset.

58. The relevant paragraph of the draft guiding princi-ple on grounds for invalidity could read as follows:

“4. Coercion of the person who formulated a uni-lateral act may be invoked as grounds for declaring its invalidity if that person formulated it as a result of acts or threats directed against him or her.”

b. Coercion of a State by the threat or use of force

78 Yearbook … 1999 (see footnote 48 above), p. 207, para. 109, art. 7 (d).

79 Yearbook … 2000 (see footnote 50 above), p. 264, para. 167, art. 5 (d).

80 Ibid., vol. II (Part Two), p. 97, para. 595.

59. This is the most important and most modern cause of invalidity of treaties, and its genesis and development are linked to the prohibition of the threat or use of force in international relations and the scope of that prohibition, which has put an end to one of the traditional methods of acquiring territory (annexation), a practice that was usually sanctioned by means of an international treaty. However, a number of issues directly related to this cause of invalidity must be addressed. The first relates to the type of force referred to in article 52 of the 1969 Vienna Convention; the Declaration on the prohibition of mili-tary, political or economic coercion in the conclusion of treaties, that was annexed to the Final Act of the United Nations Conference on the Law of Treaties, which reflects the position taken by a large group of States (particularly those belonging to the group of developing countries), demonstrates the gulf between these countries (which favoured a broad interpretation of the concept of force) and the restrictive position that ultimately triumphed.81 However, a question inevitably arises as to whether the same concept of force used in 1969 should be retained in the current international context or whether, with a view also to extrapolating the concept to future unilateral acts, a broader interpretation should be considered.

60. First, the second report on unilateral acts of States more or less reproduced—in almost identical terms, except for the heading—the provisions of the 1969 Vienna Convention; it therefore identified as a cause of invalidity the situation produced “[i]f the formulation of the unilat-eral act has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations”.82

61. In the course of the Commission’s deliberations, a suggestion was made to the effect that an additional cause of invalidity should be included, namely unilateral acts formulated in violation of a Security Council resolution adopted under Chapter VII of the Charter of the United Nations, for example an act of recognition adopted in vio-lation of a Council resolution which called on members of the Organization not to recognize a particular entity as a State.83 Echoing this suggestion, the third report on uni-lateral acts of States proposed that a unilateral act could be regarded as invalid “[i]f, at the time of its formulation, the unilateral act conflicts with a decision of the Security Council”,84 with no further qualification.

81 Official Records of the United Nations Conference on the Law of Treaties, First and Second Sessions, Vienna, 26 March–24 May 1968 and 9 April–22 May 1969, Documents of the Conference (United Nations publication, Sales No. E.70.V.5), document A/CONF.39/26. As Nahlik points out, loc. cit., p. 744, the Declaration was the result of a compromise reached between the two positions, which limited article 52 of the Convention to such cases as would fall under the prohibition already found in the principles contained in the Charter of the United Nations.

82 Yearbook … 1999 (see footnote 48 above), p. 207, para. 109, art. 7 (e).

83 Ibid., vol. II (Part Two), p. 136, para. 560. This suggestion was made by Mr. Dugard (ibid., vol. I, 2595th meeting, para. 24) and also by Poland in the Sixth Committee (Official Records of the General Assembly, Fifty-fourth Session, Sixth Committee, 25th meeting, para. 122).

84 Yearbook …2000 (see footnote 50 above), p. 264, para. 167, art. 5 (g).


62. The debates that have taken place within the Com-mission itself as to whether or not to include this sub-paragraph have been difficult: while some members have expressed support for the proposal, others have proposed that the scope of the subparagraph should be more lim-ited, and still others have called for its deletion. There is no doubt that cases may arise in which a unilateral act might conflict with a Security Council decision adopted after the act was formulated; this would not necessarily lead to invalidation of the unilateral act, but instead may simply lead to its suspension until such time as, to cite an example, a Council sanction is lifted.85 It might be appro-priate to ask whether such a situation—relating to Council decisions—is covered by the provisions on peremptory norms, which are binding for all States. The basis for this could be an interpretation of Article 2, paragraph 6, and Articles 25 and 103 of the Charter of the United Nations;86 accordingly, unilateral acts formulated in violation of such a norm would not be valid, and the operation of those formulated prior to the adoption of that norm would be suspended until such time as the decision was no longer in effect. The Commission should carefully consider and decide whether such a ground for invalidity should be included.

63. A further issue relating directly to the use of force and to the current normative framework concerns recog-nition and the role that it plays. Here the Special Rappor-teur comes into conflict with those who subscribe to the doctrine of “limits on freedom of recognition”. One of the most relevant of those limits, potentially falling within the scope of the subject that is of concern here, is that relating to the non-recognition of States founded through inter-vention or the use of force.87

64. Various cases are cited in registries of practice, which refer to numerous circumstances relating to rec-ognition, such as the Fritz Jellinek and others v. Victor G. Lévy case resolved by the Commercial Court of the Seine in its decision of 18 January 1940, in which the Court refused to consider valid the expropriation of assets and other acts leading to the use of force by Germany

85 Ibid., p. 98, para. 601.86 Assuming, of course, that interpretation of those articles is not

strictly literal; for example, Article 103 of the Charter should provide for obligations undertaken not only through treaties but also through unilateral acts if it is to apply in such cases. The Article states that: “In the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreement, their obligations under the present Charter shall prevail.” From this it could logically be inferred that any unilateral act conflicting with such a provision would have no effect. In that respect, Article 25 of the Charter, which establishes that “[t]he Members of the United Nations agree to accept and carry out the decisions of the Security Council in accordance with the present Charter”, clearly defines the nature of those decisions. Moreover, if the Special Rapporteur limits his consideration to decisions relating to the maintenance of international peace and security, the Charter even provides for application with respect to non-Member States of the Organization—whose number today is negligible—under Article 2, paragraph 6, which states that: “The Organization shall ensure that states which are not Members of the United Nations act in accordance with these Principles so far as may be necessary for the maintenance of international peace and security.”

87 On this subject, see Rodríguez Carrión, Lecciones de Derecho Internacional Público, p. 92, for a discussion of those limits and various examples.

against Czechoslovakia;88 the Court of Paris, in its deci-sion of 21 July 1953 concerning the case of Adminis-tration des Domaines v. Dame Sorkin, affirmed that no legal effects would follow from annexation or forced occupation,89 as previously ruled by the Criminal Divi-sion of the Court of Cassation in its decision of 24 July 1946 (case of Wagner and others).90 Similar rulings are found in many other case-law decisions.91 More recent cases include non-recognition of the annexation by Israel of the Golan Heights and the ensuing protests,92 direct opposition to the creation of a Turkish Cypriot state93 and the occupation of Kuwait by Iraq.94

65. However, that position has not always been consist-ent; situations can be somewhat ambiguous as regards recognition, as in the case of Manchukuo: many States Members of the League of Nations maintained trade rela-tions with that entity and gave a certain level of recogni-tion to acts formulated by it, despite the condemnation issued by the League.95 However, there have been a num-ber of cases in which courts (usually national courts) have ruled against the recognition of certain territorial annexa-tions, considering them invalid and therefore lacking legal

88 The Court ruled that “the French courts cannot allow acts of violent dispossession carried out by the German Reich against so-called ‘non-Aryan’ citizens, on that ground alone and without appropriate indemnification, to produce any effect within the territory of the Republic” (Kiss, Répertoire de la pratique française en matière de droit international public, p. 17, para. 29).

89 Kiss, op. cit., p. 28, para. 51: “Given the fact that Auschwitz, or more precisely, Osweicim, lies on Polish territory; it follows that the local law was Polish law, which de facto annexation or occupation by force could not invalidate.”

90 Ibid., p. 29, No. 52: “Whereas the alleged declaration of annexation of Alsace by Germany, invoked as an argument, was nothing more than a unilateral act that could not modify legally the provisions of the treaty signed at Versailles on 28 June 1919 by the representatives of the German State”.

91 Ibid., pp. 30–34, recounts various similar decisions by French courts.

92 That non-recognition was expressed in numerous spheres: by the United States, the Ministries for Foreign Affairs of States members of the European Community, the Governments of Arab States, the Security Council, the General Assembly and the annual World Health Assembly of WHO, among others (see Rousseau, “Chronique des faits internationaux” (1982), pp. 596–598, and Marston, “United Kingdom materials on international law 1981”, pp. 516–518).

93 When, on 15 November 1983, a Turkish Cypriot state in northern Cyprus was proclaimed, the Turkish Cypriot Assembly declared that “the two peoples, Greek and Turkish, are destined to coexist side by side on the island. The new Republic will not unite with any other State. It will be non-aligned. ... The proclamation of independence will not hinder, but on the contrary facilitate the establishment of a real federation” (Rousseau, loc. cit. (1984), p. 431). The declaration was recognized by Turkey, but categorically rejected by Greece, the United Kingdom, France, the Federal Republic of Germany, Italy, the United States, Canada, Australia, India, Japan, the Union of Soviet Socialist Republics and the States of the socialist bloc. The proclamation was condemned by the Security Council and by the Council of Europe; the former considered it as legally invalid and called for its withdrawal under Security Council resolution 541 (1983) (ibid., pp. 431–432).

94 On 8 August 1990, the Spanish Office of Diplomatic Information issued the following communiqué: “The Government of Spain, in accordance with the Charter of the United Nations, considers unacceptable the acquisition of territories by force and, therefore, rejects and does not recognize the annexation of the State of Kuwait by the Republic of Iraq, proclaimed on this day by Baghdad” (Actividades, Textos y Documentos de la Política Exterior Española (Madrid, Ministry for Foreign Affairs and Cooperation, 1991), p. 53, and Revista Española de Derecho Internacional, vol. XLIII, No. 1 (1991), p. 144).

95 See Guggenheim, loc. cit., p. 229.


effect,96 particularly since the Second World War. To some extent this issue is related directly to section (c) below, which concerns the presumed invalidity of a unilateral act that is contrary to a peremptory norm.

66. The following guiding principle could be formu-lated under principle 7 (Invalidity of unilateral acts):

“5. Any unilateral act formulated as a result of the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations is invalid.”

(c) Invalidity of a unilateral act on the ground that it is contrary to a norm of jus cogens

67. The capacity to formulate unilateral acts is funda-mentally limited by jus cogens norms,97 since any uni-lateral act that conflicts with such norms is invalid, if it is assumed that the provisions of article 53 of the 1969 Vienna Convention apply98 in general, and again mutatis mutandis, to unilateral acts.

68. Leaving aside the various opinions as to what norms might have the status of jus cogens,99 and the dif-ficult debates that led ultimately to the inclusion of that

96 Many of these cases are cited by Guggenheim, loc. cit., p. 232, and are also recounted in Lauterpacht, Annual Digest and Reports of Public International Law Cases, Years 1919–1942, case No. 123, decision of the Cantonal Court of Utrecht, the Netherlands, of 8 September 1941; ibid., Years 1943–1945, case No. 9, p. 226, non-recognition by the United States of the annexation of Estonia, and cases Nos. 8 and 54, pp. 23 and 188, contained in the same volume, relating to recognition of the annexation by Germany of Austria; and ibid., Years 1935–1937, case No. 38, p. 119, resolved on 11 May 1937 by the British Supreme Court.

97 However, some authors are highly critical of the application to unilateral acts of tenets of treaty law relating to jus cogens. For example, Weil, “Le droit international en quête de son identité: cours général de droit international public”, p. 282, writes that: “In short, one must cease referring to jus cogens in relation to unilateral acts or actions by States, and leave that theory to treaty law, where it should have remained.”

98 Article 53 (Treaties conflicting with a peremptory norm of general international law (“jus cogens”)) stipulates:

“A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. For the purposes of the present Convention, a peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.”99 Examples of these opinions can be found in Alexidze, “Legal nature

of jus cogens in contemporary international law”; Carrillo Salcedo, “Reflections on the existence of a hierarchy of norms in international law”; Casado Raigón, Notas sobre el “jus cogens” internacional; Casado Raigón and Vázquez Gómez, “La impronta del ius cogens en el proyecto de artículos de la Comisión de Derecho Internacional sobre la responsabilidad del Estado por hechos internacionalmente ilícitos”; Danilenko, “International jus cogens: issues of law-making”; Fernández Tomás, “El ius cogens y las obligaciones derivadas de normas imperativas: entre el mito y la realidad”; Gaja, “Jus cogens beyond the Vienna Convention”; Gómez Robledo, “Le ius cogens international: sa genèse, sa nature, ses fonctions”; and El ius cogens internacional: estudio histórico-crítico; Gutiérrez Espada, “Sobre las normas imperativas del derecho internacional”; Hannikainen, Peremptory Norms (Jus Cogens) and International Law: Historical Development, Criteria, Present Status; Nicoloudis, La nullité de jus cogens et le développement contemporain du droit international public; Rozakis, The Concept of jus cogens in the Law of Treaties; Sztucki, Jus cogens and the Vienna Convention on the Law of Treaties; Verdross, “Jus dispositivum and jus cogens in international law”; Virally, “Réflexions sur le jus cogens”; and Weiler and Paulus, “The structure of change in international law or is there a hierarchy of norms in international law?”.

concept in the 1969 Vienna Convention,100 the relation-ship between the unilateral act and the fact that it may conflict with a jus cogens norm will now be examined. In considering that question it should be borne in mind that, as pointed out by Brownlie: “The particular corollaries of the concept of jus cogens are still being explored.”101

69. Peremptory norms “are a constraint on the capacity to formulate unilateral legal acts; this would include some norms deriving from the Charter of the United Nations and others contained in basic conventions, such as those relating to slavery and genocide, among many others”.102 Any unilateral act conflicting with such a norm would be considered invalid ab initio; it could therefore be expected to cause protests from the time of its formulation. How-ever, practice in this regard is virtually non-existent.103

70. Following the same line of argument, it is relevant to highlight opinion No. 10 of 4 July 1992 rendered by the Arbitration Commission of the International Conference on the Former Yugoslavia (Badinter Commission) with refer-ence to recognition of the Federal Republic of Yugoslavia (Serbia and Montenegro). Paragraph 4 of that text states that:

[W]hile recognition is not a prerequisite for the foundation of a State and has only declarative value, it is none the less a discretionary act which other States may perform when they choose and in a manner of their own choosing, subject only to respect for the guiding norms of general international law, particularly those which prohibit the use of force in relations with other States or those which guarantee the rights of ethnic, religious or linguistic minorities.104

It is interesting to note that the paragraph presents “guid-ing” or peremptory norms as limiting freedom of recog-nition, from which it is logical to infer that such norms apply to all unilateral acts, of which recognition is but one example, and perhaps the most controversial of all.105 In that regard, it is appropriate to recall the position that was adopted by virtually the entire international com-munity with respect to the non-recognition of the South African Bantustans106 or the presence of South Africa in

100 See Yearbook … 1999 (footnote 48 above), pp. 209–210, para. 139.

101 Brownlie, Principles of Public International Law, p. 490.102 Yearbook … 1999 (see footnote 48 above), p. 210, para. 140.103 As pointed out by Verzijl, International Law in Historical

Perspective, pp. 76–77: “As concerns unilateral acts, I only cite here the cases of occupation of a part of the high seas, for example contiguous to the territorial sea; the annexation of foreign territory in the course of a war prior to the conclusion of a peace treaty …; a declaration of contraband relative to objects and materials which are insusceptible of such a declaration; adherence or accession to an open convention contrary to the conditions upon which the admissibility of such an adherence or accession depends; the establishment of a so-called pacific blockade pretending to produce legal effects to the detriment of a third State, etc.”

104 A/48/874-S/1994/189, annex. As highlighted by Navarro Batista, “La práctica comunitaria sobre reconocimiento de Estados: nuevas tendencias”, p. 484, attention should be drawn to the “conditionality” to which the acts of recognition in question are subject in such cases. Hence the author affirms that “[i]n reality, the efforts undertaken in the literature to underline the unconditional nature of acts of recognition seem to be less a reflection of State practice than a (laudable) attempt to restrict a reality that is considered rather unfortunate and too susceptible to political fickleness”.

105 See Verhoeven, “La reconnaissance internationale: déclin ou renouveau?”, in particular pp. 32–39.

106 The Minister of State, Foreign and Commonwealth Office of the United Kingdom responded as follows:


Namibia;107 the policy of apartheid pursued in those ter-ritories and the obstacles to Namibia’s independence were cited, respectively, as the grounds for non-recognition of situations conflicting with true peremptory norms.108 States are increasingly voicing opposition to the adoption by other States of internal norms that conflict with certain non-derogable norms.109

71. In view of the above, a possible guiding princi-ple, following on from the above-mentioned paragraphs, could be as follows:

“6. Any unilateral act which at the time of its formu-lation is contrary to (or conflicts with) a peremptory norm of general international law (jus cogens) is invalid.”

72. Having analysed the various possible grounds for invalidity that might be invoked with respect to a unilateral act, one must ask oneself who would have the authority to declare the presumed invalidity of that act, and what pos-sible channels might be established under international law—bearing in mind that one is in the territory of legal speculation—to give effect to such a declaration. This is a highly abstract area in which, if a third party (usually an international court of law or arbitration) could declare, ex officio or otherwise, the invalidity of a unilateral act, most of those ambiguities would disappear. However, it is clear that what would presumably be gained in terms of legal certainty would be lost in terms of the very essence of unilateral acts, which would be subject to a regime that was not accepted for inclusion even in the 1969 Vienna Convention.

73. What does appear to be logical is that a State that formulates a unilateral act should normally be able to invoke its invalidity, with the caveat that special attention must be paid to good faith in this context; otherwise, any

“The United Kingdom, like all other countries except South Africa, do not recognise Transkei, Bophuthatswana, Venda and Ciskei as independent, sovereign States. British officials therefore do not have any dealings with anyone who purports to represent their so-called ‘Governments’.”

(Marston, loc. cit., 1982, p. 358)107 The Minister of State, Foreign and Commonwealth Office of the

United Kingdom stated that:“The question of recognition does not arise. As a matter of

fact, a system of courts exists in Namibia as part of South Africa’s administration of that territory. We do not recognise that South Africa has any right to continue to administer Namibia ... We do not intervene during the course of judicial proceedings in Namibia or elsewhere and that has been the policy of successive governments.”

(Ibid., 1987, p. 528).108 On this issue, Cassese, International Law, p. 144, states that: “It

would follow among other things that whenever an entity with all the hallmarks of statehood emerges as a result of aggression, or is grounded on systematic denial of the rights of minorities or of human rights, other States are legally bound to withhold recognition.”

109 See, inter alia, the example cited by Cassese, ibid., p. 430, endnote No. 94, concerning the message relating to the International Convention on the Prevention and Punishment of the Crime of Genocide and the corresponding revision of criminal law sent to the Parliament by the Federal Council of the Swiss Government on 31 March 1999, which stated that: “Given that the prohibition of genocide is a peremptory norm of jus gentium (jus cogens), States cannot agree to reject it. Therefore, a peace treaty that sanctions amnesty for acts of genocide should not be considered as legally valid. Consequently, from the perspective of international law, a national law that authorizes or itself prescribes an act of genocide against a certain group may in no case serve to legitimize the conduct of the perpetrators of such an act or their accomplices.”

State wishing to eliminate commitments that it had under-taken previously through unilateral acts would declare those acts invalid ipso facto, thus creating a situation of considerable uncertainty and raising numerous doubts as to the seriousness with which that State conducts its for-eign policy, and conflicting with the very spirit in which such acts are examined, which seeks to ensure confidence and legal certainty in international relations. In that con-text, good faith assumes a role of particular importance when such commitments are undertaken.

74. However, are all grounds for invalidity equal, or should key distinctions be made between them with respect both to their effects and to who is authorized to declare such invalidity? In principle, if the same criteria that emerged from the United Nations Conference on the Law of Trea-ties—which gave rise to the 1969 Vienna Convention—are applied, a dual regime may emerge. Thus, one could speak of relative or partial invalidity (with reference to articles 46–50 of the Convention) in cases where the invocation of invalidity is regarded essentially as the exclusive right of the party affected and the effects of such invalidity are limited, except where the ground invoked is the illicit con-duct of another party. So-called “absolute” invalidity would apply in the event of invocation of one of the other grounds for invalidity cited above (coercion—of a representative of a State or of a State—or incompatibility between the act and a jus cogens norm), in which case invalidity may be invoked not only by the State that formulated the treaty (or, for present purposes, the unilateral act), but also by any other State, bearing in mind the much more serious nature of these circumstances.

75. As in other areas of international law, the problem lies in the impossibility of identifying a body that has the competence to ensure that unilateral acts comply with this regime or the authority to declare an act invalid, either ex officio or by submission of the State that formulated the act or of a third State aware of the existence of that ground for invalidity. Given that problems in addressing this issue have already arisen in relation to international treaties, an area in which normative channels appear to be much more clearly defined, the Special Rapporteur believes that with respect to unilateral acts it is all but impossible, given the current international situation, to propose and adopt a mechanism to settle any disputes that may arise in con-nection with unilateral acts and their possible invalidity. The very term “unilateral” suggests that perhaps the only viable and genuine alternative could be for the State that has formulated the unilateral act to function as the entity that has the authority—and the obligation, if the gravity of the case so requires—to draw attention to any defects in the act, thereby making the situation known and prevent-ing the act from continuing to produce effects.

76. Of course, the consideration of this topic is funda-mentally speculative, since applicable law is still somewhat uncertain, despite the effort to draw up guiding principles on the subject. In any event, as in the context of the law of treaties, the topic is important, if controversial. It should be studied in a possible subsequent phase of the work in this area.

77. Another question which is related to the invalid-ity of unilateral acts and to which there is no generally accepted answer is whether or not a presumably invalid


unilateral act can be validated. The answer to this ques-tion, whether affirmative or negative, must be qualified to reflect the particular circumstances of each case, as no definitive “yes” or “no” answers can be given in relation to unilateral acts. It could, in any case, be argued that, with respect to especially serious grounds for invalid-ity—coercion or the fact that the unilateral act in ques-tion conflicts with a norm of jus cogens—the possibility of validation is quite remote.110 The situation is likely to be different, or at least the validation is unlikely to be so problematic, with respect to other circumstances that can give rise to invalidity. Cases of error, fraud or a representative’s overstepping his or her authority, among others, probably could be validated if the subsequent conduct of the State having formulated the unilateral act clearly war-ranted that consequence.

78. Even ICJ, in some of its judgments, points to this possibility of validation, although the judgments in ques-tion refer to international treaties. This was clearly appar-ent, for example, in the ruling handed down in the case concerning the Arbitral Award Made by the King of Spain on 23 December 1906.111 Similarly, the judgment in the case concerning the Temple of Preah Vihear is also very illustrative, although it actually addresses the question of whether the subsequent conduct of one of the parties to a dispute can be deemed to validate a purportedly erroneous initial act.112

B. Termination and suspension of unilateral acts and other related concepts

79. Having considered possible grounds for the inva-lidity of unilateral acts, the application of such acts will now be examined, especially with regard to the duration of their effects over time. This includes the termination, suspension, modification and revocation of an act.

110 Except in situations that are almost purely hypothetical; for example, if a new norm of jus cogens were to emerge with which the unilateral act previously considered invalid is consistent, or even if a fundamental change in circumstances were to prompt a State to formulate a unilateral act that is identical in substance to an act formulated under coercion, even though the element of coercion is absent in the case of the latter act. If the intention of the State that formulates the new unilateral act is to apply it retroactively to the time when the presumably invalid act was formulated, should that right be denied or, conversely, should the previous unilateral act be validated without qualification? The Special Rapporteur believes that the latter option is valid if it accurately reflects the State’s intention.

111 Arbitral Award Made by the King of Spain on 23 December 1906, Judgment, I.C.J. Reports 1960, especially pp. 213–214), in which it is stated that:

“In the judgment of the Court, Nicaragua, by express declaration and by conduct, recognized the Award as valid and it is no longer open to Nicaragua to go back upon that recognition and to challenge the validity of the Award. Nicaragua’s failure to raise any question with regard to the validity of the Award for several years after the full terms of the Award had become known to it further confirms the conclusion at which the Court has arrived. The attitude of the Nicaraguan authorities during that period was in conformity with Article VII of the Gámez-Bonilla Treaty which provided that the arbitral decision whatever it might be—and this, in the view of the Court, includes the decision of the King of Spain as arbitrator—‘shall be held as a perfect, binding and perpetual Treaty between the High Contracting Parties, and shall not be subject to appeal’.”112 Temple of Preah Vihear, Merits, Judgment, I.C.J. Reports 1962,

pp. 22–24 (among others).

80. In relation to unilateral acts, the principle of good faith is a kind of substantive paradigm that implies that such acts should be maintained over time. Logically, as Barberis notes, “the author of a unilateral legal act does not have the power to establish arbitrarily, by means of another unilateral legal act, a rule that derogates from the one established by means of the earlier act”.113 Virtually the same opinion has been expressed by Venturini, who notes that, with respect to unilateral acts, “revocation is admissible only in the case envisaged by the general norms of the international legal system, because other-wise, the compulsory value of those same acts would be abandoned to the arbitrary power of their authors”.114

81. The Commission is faced with the arduous task of trying to identify the rules of general international law under which a unilateral act may be revoked.115 The Spe-cial Rapporteur wonders whether there is any certainty to be derived from international practice in this area—of which there has been very little—or from the literature—which also offers few examples—as to what circum-stances would make it permissible to terminate, modify or suspend the application of a unilateral act.

82. Before venturing into this uncharted territory, the various concepts to which reference will be made must be defined, at least at a basic level: the possibility of termi-nating a unilateral act (although in many cases the litera-ture uses the term “revocation” to refer to this situation, since it concerns unilateral acts) and the possibility of suspending a unilateral act or modifying its content; this last situation often entails the formulation of a new unilat-eral act (or even the conclusion of a treaty containing the modified version of the original unilateral act). The cases that can arise in this connection are as varied as interna-tional circumstances themselves. An attempt will there-fore be made to cover as many hypothetical situations as possible, bearing in mind, however, that neither practice nor the literature offers much information in this regard. Accordingly, relevant treaties must be investigated, by identifying possibilities that can be extrapolated to uni-lateral acts as a category, and an attempt must be made to determine the consequences that might ensue for such acts.

83. In relation to unilateral acts, two terms are used interchangeably in the literature to refer to the cessation of the effects of an act of this kind: “revocation”, which is used very frequently, and “termination”, which is of course implied by the other term. In the view of the Spe-cial Rapporteur, there is a nuance of meaning that differ-entiates between the two concepts, even though they are used interchangeably. Termination may be due to external factors (such as a situation in which the subject matter of the unilateral act has ceased to exist or a fundamen-tal change has taken place in the circumstances that gave rise to the act) or even intrinsic ones (the inclusion of a

113 Barberis, “Los actos jurídicos unilaterales como fuente del derecho internacional público”, p. 113.

114 Venturini, loc. cit., p. 421.115 As early as 1998, when the Special Rapporteur submitted his first

report on unilateral acts of States, some members of the Commission mentioned the need to study these issues; see the views of Mr. Hafner and Mr. Yamada, Yearbook ... 1998, vol. I, 2526th meeting, pp. 56–57, paras. 71–72, and of Mr. Pambou-Tchivounda and Mr. Herdocia Sacasa, ibid., p. 57, paras. 76–78.


time limit or even a resolutive condition in the unilateral act, provided that its purpose is legitimate and it does not impose obligations on third parties without their consent). The term “revoke” implies that something (in this case, a unilateral act) is considered to have been terminated or to have no further effect because the State having formu-lated it so intends.116 The Special Rapporteur believes that the word “termination” is broader, as it also covers other situations in which a unilateral act ceases to have effect as a result of circumstances unrelated to the will of the State having formulated the act.

84. Suspension—unlike termination, which is defini-tive—means the provisional and temporary cessation of the observance of the unilateral act in question. Contrary to what might, in principle, be assumed, these two con-cepts have many features in common; this may be one of the main reasons they are dealt with together in the 1969 Vienna Convention, in part V, section 3.

85. Circumstances may arise in which unilateral acts must be adapted to reflect contemporary realities; noth-ing is immutable, and unilateral acts need not necessarily be an exception. The question, then, is why the modifi-cation of their content should not be allowed, as it is in the case of international treaties. The crucial point is that, in the case of unilateral acts, it is the will of the party formulating them that determines whether the act should continue to have the same content or whether it can be modified in some way; otherwise, one would be deal-ing with something else (a bilateral agreement, in most cases), not a unilateral act. The possibility of modifying a unilateral act is therefore the prerogative of the party having formulated it, although the changes made should not affect the essence of the original unilateral act, since, if they did, they would in fact amount to a new unilateral act that would invalidate the earlier one.

86. The absence, in the literature, of discussion of the (possible) modification of unilateral acts directly mirrors the situation with respect to the modification of treaties. This is a logical consequence of the very nature of the international system.117

116 According to the definition given in the dictionary published by the Real Academia Española (Spanish Royal Academy), the Spanish term “revocar” means to render ineffective a concession, mandate or decision. According to the Concise Oxford English Dictionary, the English term “revoke” means to “end the validity or operation of (a decree, decision or promise)”. In the 1969 Vienna Convention the term “revocation” is used in article 37; that provision was cited in the Commission by Mr. Galicki as a possible source of guidance in this regard (Yearbook ... 1998, vol. I, 2527th meeting, p. 59, para. 10).

117 Casanovas la Rosa, “La modificación de los acuerdos internacionales por la práctica posterior”, p. 330, indicates that:

“Whereas in domestic legal systems most contracts are implemented on a one-time basis and ongoing contracts are less common, in the international system there are many treaties and agreements whose purpose is to regulate the relations between the parties on a more or less permanent basis. If we add the observation that the international system does not impose the formal requirements which, in the field of private law, are necessary for the validity of many contracts, nor does it have any authorities with compulsory jurisdiction that can determine, at any given time, the exact nature of the rights and obligations of the parties in case of dispute, it may easily be supposed that the modification of agreements through subsequent practice may apply much more broadly in the international sphere than in the domestic sphere.

87. To ensure that the discussion of these concepts is based on a precise understanding of them, their content must, at the outset, be analysed.

[I]t may happen that a State formulates a promise for a term of 10 years or subjects it to certain resolutive conditions. In such cases, if the term expires or the condition is met, the promise ceases without the need for any act of revocation. Another case may occur in which the author of the promise or the waiver expressly provides for the possibility of revoking it under certain circumstances. However, if the possibility of revocation derives neither from the context of the unilateral legal act nor from its nature, a unilateral promise and a unilateral waiver are, in principle, irrevocable.118

There have also, as international case law has affirmed from time to time, been acts that can be revoked, but with certain limitations, as ICJ highlighted in the case concern-ing Military and Paramilitary Activities in and against Nicaragua, in its judgment of 26 November 1984 on the jurisdiction of the Court and the admissibility of the appli-cation. According to the Court:

[T]he right of immediate termination of declarations with indefinite duration is far from established. It appears from the requirements of good faith that they should be treated, by analogy, according to the law of treaties, which requires a reasonable time for withdrawal from or termination of treaties that contain no provision regarding the duration of their validity.119

88. Also relevant in this regard is the view expressed by Gutiérrez Espada, who states:

It seems reasonable to assume that, in principle, any unilateral act may be revoked by its author, unless the circumstances unequivocally and categorically indicate otherwise. While we may invoke the “denun-ciation” of treaties by way of analogy, we must also bear in mind that denunciation is possible only in certain conditions … the revocability of unilateral acts is likewise subject to certain limitations.120

Virtually the same position is expressed in the separate opinion of Judge Mosler in the above-mentioned case concerning Military and Paramilitary Activities in and against Nicaragua.121

89. There are some situations in which unilateral acts may be modified or terminated even though these out-comes are not genuinely intended by their author. Inabil-ity to comply, the fact that the subject matter has ceased to exist or a fundamental change in circumstances are valid reasons to terminate or modify a unilateral act, while the emergence of a new peremptory norm of general interna-tional law will terminate any unilateral act that conflicts with it.

90. When the law of treaties was being codified, Sir Gerald Fitzmaurice, who at the time was the Special Rap-porteur on the subject, submitted a draft article 22, para-graph 2 of which provided as follows (expressly referring to the possibility that a unilateral act may be revocable):

However, the discussion of situations of this type in international case law has been infrequent and, in some respects … ambiguous.”118 Barberis, op. cit., p. 113.119 Military and Paramilitary Activities in and against Nicaragua

(Nicaragua v. United States of America), Jurisdiction and Admissibility, Judgment, I.C.J. Reports 1984, p. 420, para. 63.

120 Gutiérrez Espada, Derecho Internacional Público, p. 597.121 I.C.J. Reports 1984 (see footnote 119 above), p. 466.


Unless the declaration specifies its own irrevocability, the State or States in whose favour it was made cannot object to its withdrawal or modification at the will of the declarant State; provided that, if this has consequences analogous to those indicated in paragraph 4 (c) of article 20 of the present text,122 the declarant State shall be liable to pay compensation, or make other appropriate reparation, in respect of the loss or damage caused.123

91. The content of article 37, paragraph 2, of the 1969 Vienna Convention is similar to this proposal.124 Thus, if the intention referred to in that article is absent, the right in question may be revocable;125 however, no reference is made to the possibility of reparation for potential harm caused. This issue is related to international responsibility, which the codifiers did not address.

92. Interpreting this provision and relating it directly to the issue of interest here—that is, to unilateral acts—Urios Moliner affirms, rightly in the view of the Special Rapporteur, that:

[D]eclarations of this kind are in principle irrevocable and not subject to modification, unless this possibility is implied by the terms of the declaration and the circumstances and conditions necessary for this purpose, as laid down in the declaration, are met, or the party or parties having suffered the harm give their consent, or there is a fundamental change in the circumstances that gave rise to the declaration.126

In short, the aim is to ensure the maintenance of unilateral acts, which may be terminated or have their provisions modified or suspended only in exceptional and non-arbi-trary situations.

93. It is clear that this subject area has given rise to many differences of opinion, which are directly reflected in the debates of the Sixth Committee; the idea that uni-lateral acts are irrevocable unless their addressees consent to their revocation127 has been challenged by other views. These include the position that a unilateral act may be revoked if it is made subject to a time limit or to the fulfil-ment of a condition, or to general principles such as rebus

122 This refers to a situation in which a third State, by acting in such a way as to exercise the rights conferred by the treaty, incurs damage over and above what it would have incurred if it had not so acted or had not exercised any such rights.

123 Yearbook ... 1960, vol. II, document A/CN.4/130, p. 81.124 When a right has arisen for a third State in conformity with

article 36, the right may not be revoked or modified by the parties if it is established that the right was intended not to be revocable or subject to modification without the consent of the third State.

125 Contrary to what might be assumed, and according to Capotorti, “L’extinction et la suspension des traités”, p. 496, on this point the 1969 Vienna Convention took a significant step forward in relation to the traditional view—reflected, for example, in the draft Convention on the Law of Treaties, prepared by Harvard Law School—that rights conferred on third parties by an international treaty are in all cases revocable by the parties; at least the Vienna Convention limits this possibility to some extent, when the treaty in question so provides.

126 Urios Moliner, Actos unilaterales y derecho internacional público: delimitación de una figura susceptible de un régimen jurídico común, p. 125.

127 The representative of the Republic of Korea said that, in order to protect the rights of addressees and preserve international legal stability, it should not be permissible for States to revoke or modify unilateral acts without the consent of the other States concerned (Official Records of the General Assembly, Sixtieth Session, Sixth Committee, 15th meeting, para. 10). The representative of Belarus said that unilateral acts could be terminated by States only by agreement with subjects of international law that had taken note of them and modified their conduct accordingly (ibid., 18th meeting, para. 75).

sic stantibus,128 the exception for force majeure or other principles. It might even be said that certain acts should be considered revocable under all but the most limited circumstances.129

94. The Special Rapporteur believes that Germany was correct when, in its reply to the questionnaire on unilateral acts, it pointed out that the question of whether or not a unilateral act could be revoked could not be assessed in the abstract without regard to the concrete circumstances of the act in question; any attempt to subject the issue to an abstract, across-the-board principle would be meaning-less.130 Other State representatives supported the idea that unilateral acts could be revoked.131 The views expressed are indicative of a wide variety of approaches. An attempt will therefore be made to draw a distinction between situations that were provided for at the time a unilateral act was formulated or that stem directly from the will of the party having formulated it, on the one hand, and circum-stances in which an external factor gives rise to the change in question, on the other.

1. sItuatIons arIsIng from the wIll of the party formulatIng the unIlateral act

95. A State that formulates a unilateral act, as a manifes-tation of its will, may suspend or modify the act or limit its duration, if the intent to do so was clearly expressed, like the unilateral act in question, at the time or times when the act was formulated.

96. Logically, it should be possible to impose a time limit on a unilateral act132 by clearly stating this condition at the time the act is formulated. The Special Rapporteur believes that the same logic would apply in the case of a suspension of operation, if some sort of moratorium—or period during which the act shall not apply—is provided

128 The representative of the Republic of Korea said that the principle of rebus sic stantibus could also be considered as grounds for the revocability and modification of unilateral acts (ibid., 15th meeting, para. 10).

129 See also the summary of the discussion held in the Sixth Committee after the introduction of the Special Rapporteur’s second report on unilateral acts of States (Topical summary of the discussion in the Sixth Committee on the report of the Commission during the fifty-fourth session of the General Assembly (A/CN.4/504 and Add.1), para. 156).

130 Yearbook … 2000, vol. II (Part One), document A/CN.4/511, pp. 266–267. As far back as 1973, Verzijl, op. cit., expressed the same view, p. 106, stating: “Their susceptibility of unilateral withdrawal depends on their specific character and cannot, therefore, be discussed as a problem capable of a solution which applies to all cases.” The same idea was expressed in the Sixth Committee, at its sixtieth session, by the representative of Japan (Official Records of the General Assembly, Sixtieth Session, Sixth Committee, 14th meeting, para. 54), who noted that his Government considered that the revocability and modification of unilateral acts depended on the form, content, authors and addressees of the act, and must be determined by examining each category or type of unilateral act.

131 These included the representatives of El Salvador and Georgia, although Finland, Israel and Italy took a more nuanced approach by referring to that possibility, but with certain limitations (see Yearbook … 2000 (footnote 130 above), p. 281).

132 Such a time limit may, as in the case of international treaties, take various forms: a fixed date, the passage of a period of time or the fulfilment of a given event which acts as a resolutive condition are perhaps the most common forms. The time limit may even be determined by the cessation of a given activity, which implies the acceptance of an obligation from that moment onward.


for at the time of its formulation. The act would regain its legal effects at a later date (once the period provided for had expired or the established condition had been fulfilled).

97. The termination, suspension or modification of a unilateral act becomes more complex when the possibility of doing so is not—as is more often the case—provided for at the time the act is formulated. In this case the ques-tion arises as to whether it is possible to do so, taking into account that it would be the State which formulated the act that also seeks to terminate it. The question becomes even more complex in the case of unilateral acts which have generated, or which may generate, expectations among third parties. The little information to be gleaned from practice and from the literature is discussed below.

98. It has been asserted that, in general terms, the author of a unilateral promise may revoke it or modify its con-tent, provided that the addressees of the promise have expressly given their consent, or that there is no opposi-tion from the persons affected by it. This idea, which may appear very reasonable in theory, is less so in the case of a promise which has erga omnes effects,133 or whose addressees are undetermined, or where there are doubts as to their identity. Rubin makes an interesting point in this context, asserting that

it is certainly possible in some cases for a single party legally to ter-minate its apparent treaty obligations without violating the principle of good faith. There is no apparent reason why obligations assumed by unilateral declaration should be harder to terminate than obligations assumed by treaty.134

99. In the Security Council, the representative of France expressed a similar sentiment with respect to Egypt’s declaration on the Suez Canal.135 He then proceeded to question the declaration’s irrevocability, which he did not believe to have the same value as the promise itself, stating: “[A] unilateral declaration, even if registered, obviously cannot be anything more than a unilateral act, and we must draw the conclusion from these findings that just as the Declaration was issued unilaterally, it can be amended or annulled in the same manner.”136 The Secretary-General adopted an almost identical position at a press conference held on 25 April 1957 concerning the same declaration.137 Because this was a period when

133 See Sicault, loc. cit., p. 650.134 Rubin, “The international legal effects of unilateral declarations”,

p. 10.135 Declaration (with letter of transmittal to the Secretary-General

of the United Nations) on the Suez Canal and the arrangements for its operation (Cairo, 24 April 1957), by which the Government of Egypt undertook to abide by its obligations under the 1888 Convention respecting the Free Navigation of the Suez Maritime Canal (United Nations, Treaty Series, vol. 265, No. 3821, p. 299).

136 Official Records of the Security Council, Twelfth Year, 776th meeting, para. 59. See also Kiss, op. cit., p. 618. A virtually identical position regarding the possibility of revoking a unilateral act was also taken by the Minister for Foreign Affairs of France during a meeting of the Ministers for Foreign Affairs of France, the Soviet Union, the United Kingdom and the United States, held in Geneva on 8 November 1955: “It is quite true that the guarantees currently enjoyed by the USSR because of the existence of the measures taken by Western defence organizations are unilateral in nature, and therefore revocable” (ibid., p. 618).

137 In which he stated: “The registration as such does not make the document irrevocable, because it is ... binding upon the party submitting

even the very definition of a unilateral act was unclear, the intent of the formulating State affected the possibility of revoking such an act.

100. The main problem lies in the fact that a promise generates—or may generate—expectations on the part of third parties, which appear to have a certain right to assume that such a promise will be honoured, within lim-its. In this regard, Jacqué states:

A unilateral promise creates, for the benefit of its addressee(s), as soon as they are informed of its existence, a right to expect that the author of the promise will honour its commitment. However, just as treaty law authorizes the parties, under certain circumstances, to termi-nate a treaty before it expires, the Court does not guarantee the irrevo-cability and absolute immutability of a unilateral promise.138

However, in 1974 ICJ, in it own words, suggested that such a possibility of revocation is not, and is very far from being, absolute: “The Court finds that the unilateral undertaking resulting from these statements cannot be interpreted as having been made in implicit reliance on an arbitrary power* of reconsideration.”139

101. The question of whether or not a promise can be revoked raises difficult issues which can be resolved only by referring to the concrete circumstances of the case. While the principle of good faith plays a vitally important role here, since the promise generates certain expectations which could be disappointed if the promise is revoked, this undertaking need not be regarded as a perpetual obligation from which the State can never free itself. A relative, flexible position should therefore be adopted, as noted by de Visscher, “whose relativity, ratione per-sonae, ratione temporis and ratione materiae, should be seen in the light of the political and legal context of each case”.140 Such relativism may lead to problems, but the

it, with the character they have given to the document itself. That is to say ... it can be superseded ... by another declaration” (cited by Dehaussy, “La déclaration egyptienne de 1957 sur le Canal de Suez”, p. 180, footnote (32)).

138 Jacqué, “A propos de la promesse unilatérale”, p. 342.139 Nuclear Tests (Australia v. France), Judgment, I.C.J. Reports

1974, p. 270, para. 51. The Court would express a similar opinion in the case concerning Military and Paramilitary Activities in and against Nicaragua (I.C.J. Reports 1984 (see footnote 119 above), p. 418, para. 59), stating that “the unilateral nature of declarations does not signify that the State making the declaration is free to amend their scope and contents of its solemn commitments as it pleases” (The “unilateral nature of declarations” refers to declarations of acceptance of the jurisdiction of the Court, although the Special Rapporteur believes that this idea can be extrapolated in a generalized way to all unilateral declarations that may be formulated by States.)

140 De Visscher, “Remarques sur l’évolution de la jurisprudence de la Cour Internationale de Justice relative au fondement obligatoire de certains actes unilatéraux”, p. 464. Let us consider a real case in which the socio-political circumstances of the State which made the promise prevented the performance thereof. In a statement, Japanese Prime Minister Zeuko Suzuki indicated that Japan, after holding the appropriate consultations with the United States, would authorize the transit of ships carrying nuclear weapons (Rousseau, loc. cit. (1981), p. 905). He was thus publicly expressing a derogation from one of the three basic principles underlying Japan’s nuclear policy: non-possession, non-production and non-introduction of this type of weapon in Japan. The furore caused by these remarks forced the Minister to reverse course, and he subsequently announced to the press that Japan would deny such authorization. This position was reiterated on 9 August 1984 by Japanese Prime Minister M. Y. Nakasone, who, during a ceremony commemorating the nuclear attack on Nagasaki, stated that Japan would not permit United States warships carrying nuclear missiles to use its ports (ibid. (1985), p. 166).


law must be applied in a manner that takes into account its capacity to adapt to circumstances. Thus, in considering whether a promise may be changed (through termination, suspension or modification), special attention should be paid to the circumstances that make such a change neces-sary, as well as to the good faith of the State that formu-lated the unilateral act and wishes to change it. In fact, it could even be argued, moving further into the realm of alternatives characterized as de lege ferenda, that when expectations generated among third parties are seriously disappointed, it should be possible to request reparation if it can be proved that the State seeking to terminate or radically alter the content of the obligation that it assumed unilaterally is acting arbitrarily or in bad faith.

102. Turning to the concept of recognition, the Spe-cial Rapporteur finds that ideas on this subject have gone through a number of different phases, with the result that the views expressed in the literature as to whether or not an act of recognition is revocable have changed consid-erably. Practice in this area is almost non-existent, and opinions have been divided between the assertion of the irrevocable nature of recognition141 (or, at least, of what has been called de jure recognition) and de facto recogni-tion (which is considered to be provisional and therefore revocable). Since the extent of the difference of opinion is matched by the lack of any significant practice that might offer a certain degree of clarity, it is best to adopt a cau-tious approach.

103. Such caution is demonstrated, for example, by cer-tain authors who, while starting from the assumption that recognition is revocable, assert that “recognition may be revoked and there exists no right to its maintenance. However, as long as the recognition is not withdrawn, the beneficiary or beneficiaries have the right to demand that its author respect the obligations deriving from the act by which it has recognized a certain situation”.142 The same position has been taken by other authors, who distinguish between purely unilateral recognition, which they believe is revocable, and situations where an act of recognition is included in an international treaty, in which case the oppo-site effect is produced. At the present time, it seems that this position not only gives rise to many uncertainties, but also asserts a distinction whereby treaty provisions are assumed to offer more security and certainty than unilateral acts. The Special Rapporteur believes that this distinction is simply not realistic, given the current state of affairs.

104. The consequences deriving from recognition are so significant that care must be taken in making categorical assertions about its potential revocabil-ity. One complex case involved the former Yugoslav republics, which at a certain point recognized (through treaty provisions) the continuity of what was then called143 the Federal Republic of Yugoslavia (Serbia and

141 Very illuminating in this respect are the proposals noted by Verhoeven, La reconnaissance internationale dans la pratique contemporaine: les relations publiques internationales, p. 650, footnote (69).

142 Jacqué, Éléments pour une théorie de l’acte juridique en droit international, p. 337.

143 In this regard, see a discussion of the situation concerning the name of the Federal Republic of Yugoslavia in Torres Cazorla, “El último cambio de Yugoslavia: de la República Federativa de Yugoslavia (Serbia y Montenegro) a la Unión de Serbia y Montenegro”.

Montenegro);144 this situation led to an obvious contra-diction with respect to the Convention on the rights of the child. The events occurred as follows: on 3 January 1991 the Socialist Federal Republic of Yugoslavia rati-fied the Convention, making a reservation to article 9, paragraph 1,145 which it then withdrew (this time as the Federal Republic of Yugoslavia) on 28 January 1997.146 This action led to subsequent communications from Slovenia (28 May 1997), Croatia (3 June 1997), Bos-nia and Herzegovina (4 June 1997)147 and the former Yugoslav Republic of Macedonia (10 October 1997).148 Bosnia and Herzegovina, Croatia and Slovenia asserted that “[t]he State which in 1991 notified its ratification of the [said Convention] and made the reservation was the former Socialist Federal Republic of Yugoslavia (SFRY), but the State which on 28 January 1997 noti-fied the withdrawal of its reservation was the Federal Republic of Yugoslavia”.149 Moreover, they drew atten-tion to Security Council resolutions 757 (1992) and 777 (1992) and to General Assembly resolution 47/1, which indicated that the Socialist Federal Republic of Yugo-slavia had ceased to exist and that the Federal Repub-lic of Yugoslavia could not be considered its sole suc-cessor. In view of the ambiguity involved (a reserving State that has ceased to exist and a presumed successor that withdraws a reservation that it did not make), the Secretary-General was requested to clarify the situation. The former Yugoslav Republic of Macedonia stated “that the Federal Republic of Yugoslavia has neither notified its succession to the Convention, nor has it adhered to the Convention in any other appropriate manner con-sistent with the International Treaty Law. Accordingly, the Federal Republic of Yugoslavia is not, and can not be considered as a Party to the Convention”.150 Thus,

144 See paragraph 17 of the ICJ judgment of 11 July 1996, Application of the Convention on the Prevention and Punishment of the Crime of Genocide, Preliminary Objections, Judgment, I.C.J. Reports 1996, p. 610. In this case it is clear that Bosnia and Herzegovina wanted the Federal Republic of Yugoslavia to be considered as a successor State, with that position being accepted, at least with respect to the Convention, by the Court. The respective accords signed bilaterally between the Federal Republic of Yugoslavia and the other former Yugoslav republics, aimed at normalizing their relations, appeared to accept the idea of the continuity of the personality of the Socialist Federal Republic of Yugoslavia in the Federal Republic of Yugoslavia (Serbia and Montenegro). Examples in this regard include article 4 of the Agreement on the Regulation of Relations and Promotion of Cooperation between the Republic of Macedonia and the Federal Republic of Yugoslavia of 8 April 1996 (S/1996/291, appendix). See also ILM, vol. XXXV, No. 5 (September 1996), p. 1248; arti-cle 5 of the Agreement on Normalization of Relations between the Federal Republic of Yugoslavia and the Republic of Croatia, of 23 August 1996 (ibid., p. 1221; and A/51/318-S/1996/706, annex); and paragraph IV of the joint declaration of the President of the Republic of Serbia and the President of Bosnia and Herzegovina, of 3 October 1996 (A/51/461-S/1996/830, annex). See also Review of International Affairs, No. 1049–1050, p. 15. For an analysis of these and other related questions, see Torres Cazorla, “Rights of private persons on State succession: an approach to the most recent cases”, pp. 674–677.

145 United Nations, Multilateral Treaties Deposited with the Secretary-General: Status as at 31 December 2005, vol. I (United Nations publication, Sales No. E.06.V.2), p. 335, note 3.

146 Ibid., p. 340, note 38.147 Ibid.148 United Nations, Treaty Series, vol. 1993, No. 27531, p. 316.149 Ibid., Multilateral Treaties … (see footnote 145 above), p. 340,

note 38.150 See footnote 148 above.


although initially the former Yugoslav republics had appeared to recognize the continuity of the Federal Republic of Yugoslavia, they expressed the opposite view a year later.151 The complex situation in which the Federal Republic found itself for almost a decade thus illustrates how such problematic circumstances can arise.152

105. The Special Rapporteur believes that the cir-cumstances of the case, good faith and the possibility that a unilateral act may have generated expectations in third parties must be the essential elements to be taken into account in determining whether a State can put forward a further expression of unilateral will which modifies the initial unilateral act.153 However, any attempt to establish fixed rules on this subject is inevitably frustrated by the very nature of the unilat-eral act, which is infinitely flexible. The absence (albeit deliberate and desired by States) of a body responsible for considering and resolving potentially problematic situations which might arise in this respect is another important obstacle to be considered, and is at this point insuperable. The Special Rapporteur believes that only Article 33 of the Charter of the United Nations, with the freedom it allows regarding the choice of the means for the pacific settlement of disputes, can serve as a guide in this respect.

106. A situation which combines elements of the two situations mentioned above and which generally implies the possibility of terminating a unilateral act normally arises when the unilateral act in question has been per-formed in its entirety. Such cases may involve a wide vari-ety of circumstances: for example, the unilateral act may be completed through a single action (as with a promise to cancel a debt) or the obligation constituting the unilateral act may have a specific content which, once exhausted, renders the continued validity of the act futile. In a treaty context, performance serves as a reason for the expiry of so-called contractual treaties, which are defined as treaties that give rise to legal relationships of a specific nature. Once the obligation arising from such a treaty is fulfilled, the treaty ceases to operate.154

107. Various guiding principles relating to the possible grounds for termination mentioned above might be for-mulated as a single draft principle, which would initially include the following grounds, submitted for the consid-eration of the Commission:

151 An exhaustive account of this situation is contained in Torres Cazorla, “El derecho del menor a una nacionalidad: análisis de los recientes casos de sucesión de Estados”, pp. 200–201.

152 An excellent discussion of all these issues can be found in Ortega Terol, “Aspectos teóricos y prácticos de la continuidad en la identidad del Estado”, pp. 287–300.

153 This further manifestation of will which seeks to terminate the unilateral act could even consist of the signing of an international treaty whose content is contrary to that of the previous unilateral act. This could give rise to a number of possible situations: the State or States for which the previous unilateral act generated certain expectations might also be parties to the treaty, in which case no problems would occur; or they might not be parties, in which case obligations of various and sometimes contradictory kinds would arise, thereby leading to a problem of non-compliance, with either the unilateral act or the treaty. The issue of international responsibility would be a matter of considerable interest in this particular connection.

154 See Capotorti, loc. cit., pp. 525–526.

“Termination of unilateral acts (part one)

“A unilateral act may be terminated or revoked by the formulating State:

“(a) If a specific time limit for termination of the act was set at the time of its formulation (or if termination was implicit following the performance of one or more acts);

“(b) If the act was subject to a resolutive condition at the time of its formulation.”

108. Termination of a unilateral act because its subject matter has ceased to exist is to a certain degree related to another cause, which shall be considered in the next sec-tion: the potential termination, modification or suspension of operation due to supervening impossibility of perfor-mance. This cause, unlike those which are currently of concern, was included in the 1969 Vienna Convention.

2. sItuatIons arIsIng from cIrcumstances unrelated to the wIll of the party formulatIng the unIlateral act

109. The grounds for termination, modification or sus-pension of an international treaty have long been a central focus of study and have given rise to considerable misgiv-ings, particularly in cases where such changes have been brought about or intended by only one of the parties to the treaty. Although these misgivings are well founded, questions also arise with respect to other grounds where a situation unrelated to the will of the formulating State—of a unilateral act, in this case—leads to the termination, modification or suspension of the act.155 In the analysis of the different situations which could lead to such changes, the Special Rapporteur will first examine several possi-bilities that are expressly provided for in the 1969 Vienna Convention156 and that could apply to unilateral acts, and then, in the next section, other circumstances will be considered.157

(a) Situations provided for in the 1969 Vienna Convention

110. Article 61 of the 1969 Vienna Convention con-cerns a ground for terminating or suspending the opera-tion of an international treaty which, in the opinion of the Special Rapporteur, is fully applicable to unilateral acts. This ground, supervening impossibility of performance, could also justify the termination of a unilateral act if, as stated in article 61, paragraph 1, “the impossibility results from the permanent disappearance or destruction of an object indispensable for the execution of the treaty”, or the suspension of the act’s operation if the impossibility is merely temporary. The rule of ad impossibilia nemo ten-etur is fully applicable in this case, since the State would

155 This is in line with Capotorti, loc. cit., p. 514.156 The first part of the analysis will deal with supervening

impossibility of performance, fundamental change of circumstances, emergence of a new peremptory norm of general international law (jus cogens) and, to a degree, severance of diplomatic or consular relations (arts. 61–64 of the Convention).

157 These circumstances include the subsequent emergence of a new international custom, a war or State succession, all of which could result in the modification of the unilateral act in question, as will be shown.


otherwise be obliged to do the impossible. The loss or dis-appearance of an object indispensable for the execution of the unilateral act is the basic feature of this ground for termination (for example, the loss of a territory or a strip of coastline with respect to which the unilateral act pro-duced effects).158

111. The impossibility referred to in article 61, which is applicable by analogy to unilateral acts, must have the following characteristics: (a) the impossibility must be supervening; (b) the impossibility must be definitive or irreversible, since it would otherwise lead to suspension rather than termination; and (c) it must affect an object which is indispensable for the execution of the act, since the impossibility must be instrumental, although not nec-essarily physical or material.

112. An interesting question arises if the State that for-mulated the unilateral act contributed by its own conduct to the emergence of the material impossibility and is ulti-mately responsible for the loss. However, it is important to distinguish between two factors which are not differenti-ated in the 1969 Vienna Convention: the situation of loss, which could—and logically should—lead to the termina-tion or possible suspension of the unilateral act, and the possible international responsibility incurred by the State which, through its conduct, caused the material impossi-bility. This does not mean that the party concerned cannot invoke impossibility, which is a fact, but rather that it can-not be absolved of its international responsibility vis-à-vis third parties. This issue is likely to cause controversy in the majority of cases, which can be settled by the means provided under international law.

113. The invocation of a fundamental change of circum-stances as a ground for terminating an international treaty is one of the most extensively studied issues in the legal literature.159 The contrast between this ground and the rule of pacta sunt servanda is one of the most complex debates in treaty law.160 The necessary flexibility of the interna-tional order, where the will of the State and the external reality that determines it play a fundamental role, demon-strates the significance of this clause; this is only logical since the strict application of the pacta sunt servanda prin-ciple, without exception, “will violate the pacta principle itself by giving it a sacred, almost mystical, character and

158 As noted in the literature, this circumstance is somewhat similar to a fundamental change of circumstances, which will be analysed further on. In “Terminación y suspensión de los tratados”, p. 103, Ruda writes:

“It is undeniable that the disappearance or destruction of the object of the treaty constitutes a fundamental change in the circumstances that existed at the time the treaty was concluded, but the International Law Commission interprets these situations as two legally distinct grounds. The difference, in our understanding, is that supervening impossibility of performance is an objective criterion, whereas a fundamental change of circumstances is determined subjectively; this distinction is worthy of separate study.”159 See Haraszti, “Treaties and the fundamental change of

circumstances”, pp. 46–64.160 The bibliography on this subject is extensive. The Special

Rapporteur will simply mention the statement made by Van Bogaert prior to the conclusion of the studies which led to the 1969 Vienna Convention, “Le sens de la clause ‘rebus sic stantibus’ dans le droit des gens actuel”, p. 50, to the effect that “[i]t is useful to note that pacta sunt servanda and rebus sic stantibus are the two elements which ensure that the law is efficient and, at the same time, equitable”.

elevating it to a noli me tangere”.161 The importance of this ground for termination may be the primary and ultimate reason for the degree of detail and the negative wording of article 62 of the 1969 Vienna Convention, which limit the possibility of invoking that circumstance. This reflects the restrictive position taken in the literature on the pos-sible invocation of this ground, as a logical consequence of the need to prevent arbitrary actions which otherwise might be taken. Regarding the fundamental character that the changed circumstance must have, it has been logically affirmed in the literature that

[t]he changed circumstance must be fundamental; it must affect, as has been said, the fundamentum or very basis of the treaty, and must be extraordinary in that it transcends or exceeds the ordinary changes that are rightly and typically anticipated in the drawing up of private con-tracts or international treaties.162

114. The definition of a fundamental change of circum-stances is subject to a wide variety of interpretations and may even be applied to a situation of war between the parties. In the Rann of Kutch case between India and Paki-stan, India compared the Ihlen declaration, which was taken into account by PCIJ in the dispute between Den-mark and Norway,163 to the circumstances of the current case, declaring before the Tribunal that

the Ihlen declaration was made at a time when there was no dispute between Denmark and Norway; the attitude changed when the dispute arose subsequently. The declaration cannot be put on a par with one sentence in one letter after an acute dispute had arisen and when “par-ties are fighting each other, as it were, in correspondence over a par-ticular attitude”.164

115. It has been maintained that articles 61 (Superven-ing impossibility of performance) and 62 (Fundamental change of circumstances) of the 1969 Vienna Conven-tion165 could be applied mutatis mutandis to certain uni-lateral acts (particularly those which give rise to obli-gations), given that the conditions for modification and termination are very close to those provided for in treaty law with respect to the suspension or termination of obli-gations arising from an international treaty.166 However,

161 Poch de Caviedes, “From the clausula rebus sic stantibus to the revision clause in international conventions”, p. 168.

162 Ibid., p. 170.163 Legal Status of Eastern Greenland (see footnote 57 above), p. 70.164 International Law Reports (London), vol. 50, 1976, p. 379. See

also the case concerning the Indo-Pakistan Western boundary (Rann of Kutch) between India and Pakistan, UNRIAA, vol. XVII, p. 410.

165 According to Sicault, loc. cit., pp. 654–655, a fundamental change of circumstances may be invoked by a State that formulates a unilateral promise as a ground for revoking the promise, if the following three conditions are met: (a) the existence of those circumstances must have constituted an essential basis of the consent to be bound by the promise; (b) the change of circumstances must radically transform obligations still to be performed under the unilateral act; and (c) the change of circumstances must not have resulted from a breach by the author of the promise of an international obligation (either of an obligation under the promise or of any other obligation).

166 There is one particularly sensitive area in which States often show great suspicion or formulate protests when other parties adopt controversial conduct: issues related to disarmament or to moratoriums on nuclear testing. What is more, States often make commitments that are not strictly unilateral, but are directly related to the conduct of another State. One example of this was the announcement by the Soviet Union on 18 December 1986 that it would resume nuclear testing whenever the United States did so, thereby ending the moratorium which had been in place since 6 August 1985. After the United States conducted an underground nuclear test on 3 February 1987 at the Nevada nuclear testing ground (followed by further tests on 11 February and 18 March),


in the context of unilateral acts such situations entail an additional circumstance which normally does not occur in treaty law, namely the unilateral modification of the content of the unilateral act. This explains the cautious attitude of ICJ in its consideration of the invocation of a fundamental change of circumstances, as shown by the Gabčíkovo-Nagymaros Project case:

A fundamental change of circumstances must have been unforeseen; the existence of the circumstances at the time of the Treaty’s conclusion must have constituted an essential basis of the consent of the parties to be bound by the Treaty. The negative and conditional wording of Article 62 of the Vienna Convention on the Law of Treaties is a clear indication moreover that the stability of treaty relations requires that the plea of fundamental change of circumstances be applied only in exceptional cases.167

116. Sometimes the psychological element or the belief by the formulating State that there has been a fundamental change in the circumstances that prompted it to adopt its initial position take on special importance. An interesting example is the position adopted by Poland, which initially notified ILO of its withdrawal from that organization and subsequently invalidated the withdrawal through another notification the day before the initial notice was to have taken effect.168

117. Could the severance of diplomatic or consular rela-tions result in such a change as to bring about the termina-tion or suspension—or perhaps modification—of a unilat-eral act? In principle, if one were to follow the approach that was taken in codifying international treaties, such a severance of relations need not bring about significant changes, except as could otherwise be inferred from the contents of the unilateral act itself (for example, if diplo-matic or consular relations are a condition without which the unilateral act would not have been formulated or if it would be very difficult to carry out in the absence of this circumstance). Accordingly, article 63 of the 1969 Vienna Convention provides that:

“The severance of diplomatic or consular relations between parties to a treaty does not affect the legal relations established between them by the treaty except insofar as the existence of diplomatic or consular rela-tions is indispensable for the application of the treaty.”

The Convention uses the word “indispensable”; thus it may be inferred that the same requirement should apply to uni-lateral acts. However, the Special Rapporteur is reluctant to subscribe to that view; indeed, it is his understanding

the Soviet Government officially announced on 4 February that the United States action had ended the moratorium. The Soviet Union resumed nuclear testing on 26 February in Kazakhstan (Rousseau, loc. cit. (1987), p. 945).

167 Gabčíkovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, p. 65, para. 104.

168 On 17 November 1984, Poland, through its representative in Geneva, gave notice to the ILO Governing Body of its withdrawal from that organization. Its letter reiterated the charges it had been levelling for three years against ILO, including interference in Poland’s internal affairs, a continuing anti-Polish campaign and a hostile attitude towards Poland (Rousseau, loc. cit. (1985), p. 467). That notice would be rendered invalid when, on the morning of 16 November 1987, the Government of Poland informed the ILO Director-General that it was withdrawing its previous notice, being satisfied that the problems caused by actions taken against Poland within ILO, which had made it impossible for Poland to participate in the organization’s work, would be settled once and for all. Poland’s withdrawal from the organization was to have become effective on 16 November 1987 at midnight (ibid. (1988), p. 407).

that typically, where diplomatic or consular relations have been severed, it is highly unlikely that the State which formulated the act will be prepared to continue to carry it out, at least in the same manner.

118. The emergence of a new peremptory norm of general international law (jus cogens), as provided in article 64 of the 1969 Vienna Convention, more or less stands in logical correlation to article 53 of the Conven-tion, to which reference has already been made. Arti-cle 64 provides that: “If a new peremptory norm of general international law emerges, any existing treaty which is in conflict with that norm becomes void and ter-minates.” However, despite the words at the end of that article (“becomes void and terminates”), one is dealing here with a case of extinction upon the emergence of a norm of jus cogens and not properly of invalidity, as discussed earlier. The consequences of this are substan-tial: the effects which the treaty produced up until the new norm’s emergence will remain unaffected wherever possible, as opposed to what would occur in a case of invalidity as such. That is the major distinction between the two provisions mentioned above.

119. In view of the foregoing, the following paragraphs may be formulated with regard to other possible causes of termination under the above-mentioned guiding principle:

“Termination of unilateral acts (continued)

“A unilateral act may be terminated or revoked by the formulating State:

“...

“(c) If the subject matter of the unilateral act has ceased to exist;

“(d) If there has been a fundamental change in the circumstances that prompted the formulation of the act (rebus sic stantibus) which renders its fulfilment impossible;

“(e) If a peremptory norm of international law has emerged following its formulation which conflicts with the act.”

(b) Situations not expressly provided for in the 1969 Vienna Convention

120. An issue of relevance that arises with respect to uni-lateral acts is whether a customary rule that emerges sub-sequent to the formulation of a unilateral act may result in the termination, modification or suspension of the act as being in conflict with that rule. This issue, the answer to which is uncertain, was raised by the Commission when the law of treaties was being codified. However, the Com-mission decided, given the numerous difficulties involved in the controversial issue of the possible conflict between treaty and customary rules, that the issue was too com-plex to be covered in all its aspects without jeopardizing the work of codification and progressive development.169 Possibly, a normative basis on which to tackle this issue may be found in the area of universal or general custom;

169 See Capotorti, loc. cit., p. 518.


on the other hand, the Special Rapporteur finds regional custom more problematic, given that the existence of a unilateral act contrary to what is claimed to be regional or even local custom could act as a serious impediment to such custom gaining currency or even being opposable to the State which formulated the unilateral act. Practice shows that the opposite situation is more frequent; that is to say, the existence of many unilateral acts on a particular matter tends to bring about a change in the legal regime in effect until that time. Such a new approach may even be set forth in a treaty.170

121. A second case not addressed in the 1969 Vienna Convention is the issue as to what happens to unilat-eral acts when their author undergoes a substantial transformation. In other words, what happens in case of State succession? Should the previous undertakings entered into under unilateral acts remain in force or do such undertakings become ineffective when such a cir-cumstance occurs, especially in cases where the prede-cessor State disappears? This issue, which is not easy where international treaties are concerned,171 is even less so in the case of unilateral acts, where the conflict between two competing needs that arise at the interna-tional level becomes even more evident: the need to ensure a certain stability in international relations, with adherence to international undertakings deriving from unilateral acts being a key reflection of this. In each case, the solution will depend on the particular circum-stances, as well as whether it is still possible for the State or States emerging from the succession to comply with the unilateral act. In the view of the Special Rap-porteur, there are no criteria that point a priori to a restrictive approach one way or another. Clearly, how-ever, where a State has undergone a very significant transformation as a result of a succession, the unilateral act may as a result be modified.

122. On the other hand, there also arises the issue as to whether the outbreak of an armed conflict can cause the termination or suspension of a unilateral act in effect between the two belligerent States. As with the issue dis-cussed above, the 1969 Vienna Convention merely states

170 This is what occurred, for example, in the law of the sea with respect to the extension of the territorial sea to 12 nautical miles and the establishment of the exclusive economic zone, the origin of which is directly tied to the concept of a “patrimonial sea” (Seve de Gastón, “Los actos jurídicos internacionales unilaterales con especial atinencia a los intereses marítimos argentinos”, p. 260, who provides an overview of all these issues and an illustrative listing of unilateral acts of States (sorted by continent), ibid., pp. 260–261 and 295–357.

171 The lack of an international consensus in favour of the principle of continuity with respect to international treaties to which the predecessor was a party, as opposed to the tabula rasa approach, is becoming evident. This is demonstrated by two factors. The first is the limited acceptance of the Vienna Convention on Succession of States in respect of Treaties (hereinafter the 1978 Vienna Convention), which resulted in it not securing the number of ratifications required for its entry into force until 1996. The second factor is reflected in the many divergences observed in international practice over the last decade, with continuity, notification of succession, accession to or termination of the effects of the international treaties of the predecessor all being frequently observed. As Koskenniemi has highlighted in “Report of the Director of Studies of the English-speaking section of the Centre”, p. 89: “The only relatively undoubted normative conclusion one can draw remains procedural: that States should negotiate in good faith. That obligation is not, however, dependent on the 1978 Vienna Convention but on a structural requirement of the diplomatic system.”

that it does not cover this situation. Article 73 of the Con-vention expressly states that: “The provisions of the pre-sent Convention shall not prejudge any question that may arise in regard to a treaty from a succession of States or from the international responsibility of a State or from the outbreak of hostilities between States.” Given its contro-versial nature, this issue was set aside. The Commission has now reverted to it and appointed Mr. Brownlie as Spe-cial Rapporteur for the topic; he submitted his first report in 2005.172

123. On this point, it is the view of the Special Rap-poteur that, more clearly than in any other circumstance, the unilateral act at issue must be looked at to determine whether war affects the performance of a particular uni-lateral act. Perhaps, where the act constitutes a promise or waiver which operates to the advantage of the State with which the author State is at war, the author State may elect to terminate it or, at a minimum, to suspend it. In addition, a fundamental change of circumstances may even be invoked. A highly politicized institution such as recognition is usually subject to change in cases of armed conflict and may even give rise to other situations, such as recognition of the state of armed conflict, with the conse-quences that this entails.173

124. The above discussion on the validity, grounds for invalidity and application of unilateral acts, which is heavily influenced by the Vienna regime, is intended to complement earlier reports, to clarify these issues to the extent possible and, indeed, to provide the Commission with a set of guiding principles in this specific area. All these comments, with the exception of those relating to suspension, have already been set out in the relevant sec-tion, but the Special Rapporteur elected to reiterate them as a whole at this juncture in order not to lose sight of the overall picture.

“Suspension of unilateral acts

“A unilateral act may be suspended by the formulating State:

“(a) If a circumstance that would allow for its sus-pension was specified at the time of its formulation;

“(b) If the act was subject to a suspensive condition at the time of its formulation;

“(c) If its subject matter has temporarily ceased to exist;

“(d) If there has been a fundamental change in the circumstances that prompted the formulation of the act which temporarily renders its fulfilment impossible.”

172 In 2005, the first report on the effects of armed conflicts on treaties (Yearbook … 2005, vol. II (Part One), document A/CN.4/552, p. 209) was submitted together with a memorandum by the Secretariat entitled “The effect of armed conflict on treaties: an examination of practice and doctrine” (A/CN.4/550 and Corr.1–2), reproduced on the website of the Commission.

173 For an exhaustive discussion of this issue, see Verhoeven, op. cit., pp. 100–167.


chapter II

Draft guiding principles for consideration by the Working Group

125. As mentioned at the beginning of this report, the Commission is being provided with draft guiding principles on the various issues discussed earlier in the Commission and in the Sixth Committee. These draft guiding principles could be considered by the Working Group on unilateral acts of States to be reconvened this year. This set of guiding principles covers the validity and termination of unilateral acts, a topic discussed in chapter I of the present report.

A. Definition of a unilateral act

126. One of the most extensively debated issues in the Commission since it began considering this topic in 1997 has been the definition of a unilateral act, which is cru-cial for developing rules or guiding principles governing the operation of such acts. The first issue in this regard is the distinction between unilateral legal acts and unilateral acts of States not aimed at establishing or confirming a legal relationship; that is, unilateral political acts. From the outset, special emphasis has been placed on the need to make a distinction between the two types, which is a difficult proposition for the purposes of which it is crucial to determine the intention of the author State. Unilateral legal acts would, of course, be subject to international law and failure to comply therewith would cause the author State to incur international responsibility. Unilateral po-litical acts would commit the State only in the political context, and the State would incur only political conse-quences for non-compliance.

127. Without revisiting the topic, it should be recalled that the Commission has held detailed discussions, in the plenary and in the Working Group on unilateral acts of States, on some acts that are within the framework of international political relations and, as such, fall outside the scope of international law, including the unilateral declarations of nuclear-weapon States referred to as nega-tive security assurances, formulated at various levels and in various international bodies and contexts. In the view of the majority of members, such declarations are political in nature and as such are not legally binding on the declar-ing States. A detailed review of the texts of such declara-tions and of the circumstances or contexts in which they were formulated shows that the declaring States had no intention of entering into legal obligations in connection with such negative security assurances. These were there-fore unilateral political declarations not subject to inter-national law.

128. From the outset the members also generally agreed to single out those unilateral legal acts of States that are clearly part of a treaty relationship and as such fall under the 1969 Vienna Convention. These are acts which are unilateral in form, that is, formulated by a single State—but are part of a treaty relationship. Examples include signature, ratification, formulation and withdrawal of reservations, notification and deposit of relevant treaty instruments, among others. A unilateral act, sensu stricto, establishes a relationship between the author State and the addressee or addressees, but this relationship is distinct from a treaty relationship.

129. Another category to be identified is unilateral acts connected with a particular regime authorized by a spe-cific set of rules. Declarations establishing exclusive eco-nomic zones or, in general, the delimitation of maritime zones are examples of such acts.

130. Also excluded are declarations of acceptance of the compulsory jurisdiction of ICJ, which, although they are also unilateral as to their form, fall under the Vienna regime on the law of treaties. While such declarations are formally unilateral, most international scholarship and case law consider them as being part of a treaty relation-ship and as such falling within the Vienna regime. How-ever, these are sui generis optional declarations to which certain rules, such as the rules of interpretation, should be applied more flexibly. It should be recalled, in this regard, that in the case concerning Military and Paramilitary Activities in and against Nicaragua, the United States contended that such declarations

are sui generis, are not treaties, and are not governed by the law of treaties, and States have the sovereign right to qualify an acceptance of the Court’s compulsory jurisdiction, which is an inherent feature of the Optional-Clause system as reflected in, and developed by, State practice.174

131. While mindful of their sui generis nature, as it had been in previous cases, such as the Anglo-Iranian Oil Co. case, ICJ took the view that such declarations were indeed part of a treaty relationship. Declarations accept-ing the Court’s jurisdiction, it noted, were not a treaty text resulting from negotiations between two or more States but “the result of unilateral drafting”.175 The fact that such declarations are registered and deposited with the Secretary-General supports this view. From a reading of the Court’s 1984 judgment, it may be concluded that, even though such declarations fall under a treaty regime, the fact that they were unilaterally drafted should be taken into account when interpreting them.

132. The unilateral acts that have been under consid-eration by the Commission since 1997, namely unilateral declarations made by one or more States with a view to producing certain legal effects, should be distinguished, at least as far as their formulation or realization are con-cerned, from equally unilateral conduct which, without being an act in the strict sense of the term, is capable of producing similar legal effects. Considering both unilat-eral acts and unilateral conduct in the same study was not deemed acceptable by the majority, although some members and some Governments were of the view that their consideration should be related, since, even though they could be “formulated” or “realized” under different circumstances, they could have similar effects. Although, in the view of the Special Rapporteur, there are clear dif-ferences between acts and conduct, at least with regard to their formulation, it was felt that conduct should not be excluded from the study and from adequate consideration

174 I.C.J. Reports 1984 (see footnote 119 above), p. 415, para. 53.175 Anglo-Iranian Oil Co., Preliminary Objection, Judgment,

I.C.J. Reports 1952, p. 105.


by the Commission. The guiding principles with regard to unilateral acts in the strict sense could be applicable mutatis mutandis to unilateral conduct by States.

133. Based on the reports of the Special Rapporteur, the Commission very thoroughly reviewed a series of clas-sic unilateral acts which are considered as such by most legal scholars (recognition, promise, waiver, protest), and concluded that, while it was a useful intellectual exercise that in some ways enriched the international doctrine on the subject, the Commission was aware that the char-acterization of the act does not alter its legal effects. A unilateral act, as the Commission concluded at the time, may be characterized in various ways, without influenc-ing the legal effects that the author of the act is seeking to produce. Independently of its characterization, what was important was to determine whether the author State, at the time it formulated the act, intended to commit itself legally in relation to the addressee or addressees.

134. The unilateral act of interest to the Commission is a declaration, made by one or more States, whose form—it should be made clear—is not important and which con-tains an expression of unilateral will formulated with the intention of assuming certain obligations or of confirming certain rights. It is an act whose process of elaboration differs from the process of elaboration of a treaty in which two or more States participate; this makes it difficult to determine the intention of the author to be legally bound.

135. The author of the act seeks through such a decla-ration “to produce certain legal effects”, a more generic expression that encompasses both the obligations that the declaring State may assume and the rights that it may reaffirm through such an act. This question has been extensively debated in the literature and in the Com-mission. A State, it was affirmed, may assume unilateral obligations in the exercise of its sovereignty, but cannot impose obligations on another State without the latter’s consent, as was established in the regime on the law of treaties. However, some members expressed the view that to refer exclusively to the assumption of obligations would limit the scope of the draft articles and that refer-ence should be made to the production of legal effects that cover both the possibility of assuming obligations and that of reaffirming rights.

136. A unilateral act should be formulated “under inter-national law”, since it is itself derived from international law and thus becomes a source of obligations176 (and even of the reaffirmation of rights), like treaty or customary norms or acts of international organizations.

137. As a reflection of what has been stated above and in accordance with the results of the Commission’s delib-erations and the conclusions of the Working Group on unilateral acts of States established to consider the ques-tion, the following draft guiding principle is presented.

176 In this connection, reference must be made to the terms used by ICJ in its judgment of 3 February 2006 on admissibility in the case concerning Armed Activities on the Territory of the Congo, I.C.J. Reports 2006 (see footnote 40 above), p. 26, para. 45 (in which it uses the expression “unilateral commitment having legal effects”), and p. 27, para. 46 (in which it refers to “performance, on behalf of the said State, of unilateral acts having the force of international commitments”).

The draft text covers in general terms the constituent el-ements of the draft definition which the Special Rappor-teur presented in his first report177 and which served at the time as an initial basis of discussion to develop the study of the subject.

“Principle 1. Definition of a unilateral act

“A unilateral act of a State means a unilateral declara-tion formulated by a State with the intent of producing certain legal effects under international law.”

138. In the context of the definition and its scope, ref-erence should now be made to the addressee (or address-ees) of the act. While the subject under consideration and the draft guiding principles concern unilateral acts formulated by a State, it is important to note that such acts may be addressed to another State, to a group of States, to the international community as a whole, to an international organization or to any other entity subject to international law.

139. It is therefore necessary to include a reference to this characteristic in the definition (para. 2). The Com-mission is presented with two options for this paragraph, the first of which enumerates the possible addressees of unilateral acts, thereby giving the paragraph a more restrictive character, while the second and broader option specifies that a unilateral act must be formulated in accordance with international law, but does not specify to whom it must be addressed.178

“Principle 1

“2. Addressees of unilateral acts of States

“Option A

“A unilateral act may be addressed to one or more States, the international community as a whole, one or more international organizations or any other entity sub-ject to international law.

“Option B

“A unilateral act formulated in accordance with inter-national law will produce legal effects, regardless of to whom it was addressed.”

B. Formulation of a unilateral act

1. capacIty of a state to formulate a unIlateral act

140. As is the case under the law of treaties, the State has capacity to formulate unilateral acts. Indeed, the State may, in the exercise of its sovereignty, formulate declarations with the intent to produce certain legal effects, assuming unilateral obligations that, given their nature, do not require acceptance or any reaction on the part of the addressee. The term used is “formulate”, which is similar to the terms

177 Yearbook … 1998, vol. II (Part One), p. 319, document A/CN.4/486.

178 It suffices to recall in this regard some of the examples mentioned in the eighth report on unilateral acts of States, which include among the addressees of a unilateral act even the officers of an international organization or entities that are not States as such (Yearbook … 2005 (see footnote 1 above), p. 126, paras. 44–54 and pp. 133–135, paras. 138–156).


“elaboration” or “conclusion” used in treaty law. Indeed, it has been noted that “formulation” reflects the unilateral form of the act, while the “elaboration” or “conclusion” of a treaty presumes agreement or a common intent, which is unnecessary in the context of unilateral acts.

141. In this way, closely following the language of the 1969 Vienna Convention (art. 6), every State has capacity to formulate a unilateral act, provided, in this case, that it is done “in accordance with international law”. The guid-ing principle would therefore be drafted as follows:

“Principle 2. Capacity of States to formulate unilateral acts

“Every State possesses capacity to formulate unilateral acts in accordance with international law.”

2. persons havIng competence to formulate unIlateral acts on Behalf of a state

142. A somewhat more complex question concerning the formulation of unilateral acts is that of the competence of the persons who can formulate an act of this nature on behalf of the State and commit the State in its inter-national relations. The question has been considered by the Commission on various occasions, particularly during the debates that followed the presentation of the second and third reports on unilateral acts of States. As will be recalled, the Special Rapporteur presented some general and preliminary ideas on the subject, which were consist-ent with the opinions expressed both by the members of the Commission and by some of the States that responded to the questionnaire sent out by the Secretariat.179

143. Like the formula which must be taken as the point of departure, in accordance with the Vienna regime on the law of treaties, certain persons may without authorization act and bind the State in its international relations (Heads of State, Heads of Government and ministers for foreign affairs), on the assumption that these individuals have full powers to do so. As ICJ recently observed in accordance with its consistent jurisprudence:

[I]t is a well-established rule of international law that the Head of State, the Head of Government and the Minister for Foreign Affairs are deemed to represent the State merely by virtue of exercising their functions, including for the performance, on behalf of the said State, of unilateral acts having the force of international commitments.180

144. Paragraph 1 of the draft guiding principle, which contains this general rule, would read as follows:

“Principle 3. Competence to formulate unilateral acts on behalf of the State181

“1. By virtue of their office, Heads of State, Heads of Government and ministers for foreign affairs are con-sidered to represent their State and to have the capacity to formulate unilateral acts on its behalf.”182

179 See, for example, the opinions of Argentina and Israel, Yearbook … 2000 (see footnote 130 above), pp. 271–272.

180 I.C.J. Reports 2006 (see footnote 40 above), p. 27, para. 46.181 This heading reflects the wording suggested by Mr. Pambou-

Tchivounda (Yearbook ... 2000, vol. I, 2628th meeting, p. 128, para. 31).182 The need to have a restrictive criterion for determining who has

the capacity to bind the State through the formulation of unilateral acts was stressed by many of the States that answered the questionnaire

145. In addition to the persons referred to in draft prin-ciple 3, paragraph 1, there might be other persons who could act on behalf of the State and bind it by formulat-ing a unilateral declaration. Within the Sixth Committee, various opinions have been expressed indicating a reluc-tance to broaden the circle of persons qualified to formu-late unilateral acts.183 Moreover, within the Commission itself, a number of members cited examples to show that, although in many cases representatives to international conferences had made declarations that appeared to be binding in some way on the States they were representing, ultimately that did not prove to be the case.184

146. It is true that this provision raises many problems, as indicated above; nonetheless, it is a common practice, especially in the context of certain international bodies or organizations, for representatives of the State other than those mentioned above to perform acts by which they may and in fact do bind the State that they represent.185

147. In the Commission’s deliberations, the possibility has been put forward that persons other than the Head of State or Government or the minister for foreign affairs may also be authorized under international law to act on behalf of and bind the State in this sphere. During these debates the view has been expressed that a person other than those mentioned might act and bind the State in this sphere if that person can be considered authorized to do so. This narrow innovation would reflect the evolving nature of international relations and the possibility that some persons may be empowered to act and do in fact act on behalf of the State. The special nature of unilateral acts, in this view, makes it necessary to devise a more flexible rule than the rule for treaties, while framing it in such a way that only in specific cases and circumstances may the State be bound by persons other than those tradi-tionally contemplated under the Vienna regime.

148. In its judgment of 3 February 2006 on the jurisdic-tion of the Court and the admissibility of the application

sent out by the Secretariat (see Yearbook … 2000 (footnote 130 above), p. 265). In that regard, in a meeting of the Commission, Mr. Momtaz expressed the view that the capacity to formulate a unilateral act should be restricted to those persons mentioned in article 7, paragraph 2 (a), of the 1969 Vienna Convention (see Yearbook … 2002, vol. I, 2723rd meeting, p. 82, para. 30).

183 The representative of Chile, for instance, in discussing the possibility of adopting a flexible criterion for determining which persons should have the capacity to formulate unilateral acts, said that his delegation was opposed to adopting rules more flexible than those contained in the 1969 Vienna Convention. See Official Records of the General Assembly, Sixtieth Session, Sixth Committee, 16th meeting, para. 47, in which he stated that such flexibility was dangerous and could lead to abuses, since it was left to the addressee State to determine whether the person who had formulated a given declaration, without being formally empowered to do so, was actually authorized to bind the State that person claimed to represent. Under article 7, paragraph 1 (b), of the Convention, flexibility in the matter of representing the State was limited to the practice of the States concerned, so that the decision was not left to one State alone. The representative of Kenya agreed and expressed the view that the category of persons with capacity to bind the State should be restricted to that defined in article 7 of the Convention (ibid., para. 73).

184 See the examples cited by Mr. Hafner in Yearbook ... 1999, vol. I, 2595th meeting, p. 205, para. 34.

185 Consider, for example, what occurs when State representatives, who are of ministerial rank but are not necessarily ministers for foreign affairs, meet in the Council of the European Union.


filed by the Democratic Republic of the Congo against Rwanda, ICJ noted that

with increasing frequency in modern international relations other per-sons representing a State in specific fields may be authorized by that State to bind it by their statements in respect of matters falling within their purview. This may be true, for example, of holders of technical ministerial portfolios exercising powers in their field of competence in the area of foreign relations, and even of certain officials.186

This citation supports the notion that persons other than those authorized to act on behalf of the State in the treaty sphere may bind the State through the formulation of a unilateral statement or declaration, as can be inferred from the text of the ICJ judgment in the cited case, with refer-ence to the actions of the Minister of Justice of Rwanda.

149. The Special Rapporteur should add that, in addi-tion to the possibility of inferring from practice that a per-son may act on behalf of and bind the State that he/she represents in a given sphere, the circumstances in which a particular unilateral act has been formulated are also relevant, as will be seen below. The manner in which it was formulated, the terms of the declaration (and, as ICJ indicated, the clarity and precision of those terms) and the context, which together provide all the relevant informa-tion surrounding the unilateral act, will be critical factors.

150. On the understanding that the above question will be considered in greater detail further on in relation to the interpretation of unilateral acts, the Special Rapporteur will now present guiding principle 3, paragraph 2, which is worded as follows:

“In addition to the persons mentioned in the previous paragraph, other persons may be considered able to formulate unilateral acts on behalf of the State if that may be inferred from the practice followed in that regard by the formulating State and from the circumstances in which the act was formulated.”

3. suBsequent confIrmatIon of a unIlateral act formulated wIthout authorIzatIon

151. As is the case in treaty law, a unilateral act may be confirmed by the State when it has been formulated by a person not authorized or qualified to do so. In previ-ous reports the Special Rapporteur suggested that, given the nature of unilateral acts, such confirmation must be explicit; however, that view did not meet with broad sup-port from the members of the Commission.

152. In addition to the consideration given to the ques-tion in chapter I of the present report in relation to the grounds for invalidity of a unilateral act, the Special Rap-porteur will now present the following draft guiding prin-ciple concerning confirmation:

“Principle 4. Subsequent confirmation of an act formulated by a person without authorization (or not qualified to do so)

“A unilateral act formulated by a person not authorized (or qualified) to act on behalf of the State, in accordance with the previous guiding principles, may be confirmed subsequently by the State either expressly or through

186 I.C.J. Reports 2006 (see footnote 40 above), p. 27, para. 47.

conclusive acts from which such confirmation can be clearly inferred.”

C. Basis for the binding nature of unilateral acts

153. Since the first report on the topic was submitted to the Commission,187 the question of the basis of unilateral acts, that is, what makes them binding, has come up for discussion on a number of occasions, but there has been no unanimity of opinion on the matter. Without going into great detail and reverting to previous reports and debates in the Commission, the Special Rapporteur merely notes that neither the legal literature188 nor the members of the Commission have taken a unified position that would allow him to determine clearly what constitutes the basis for the binding nature of unilateral acts.189

154. One basic principle that must be taken into account is good faith, if the view expressed by ICJ in 1974 is followed:

One of the basic principles governing the creation and performance of legal obligations, whatever their source, is the principle of good faith. Trust and confidence are inherent in international co-operation, in par-ticular in an age when this co-operation in many fields is becoming increasingly essential. Just as the very rule of pacta sunt servanda in the law of treaties is based on good faith, so also is the binding character of an international obligation assumed by unilateral declaration. Thus interested States may take cognizance of unilateral declarations and place confidence in them, and are entitled to require that the obligation thus created be respected.190

155. Realistically, the intention of the State that formu-lated the unilateral act also constitutes an element that must be given considerable weight in determining the basis of the binding nature of unilateral acts. This opin-ion, expressed within the Commission,191 finds support in the legal literature192 and ICJ decisions.193 In the judgment of 3 February 2006 cited above, the Court reaffirmed the necessity of taking into account the “actual content [of a

187 See Yearbook … 1998 (footnote 177 above), pp. 336–337, paras. 152–162.

188 On this point, Bondía García, Régimen jurídico de los actos unilaterales de los Estados, notably on page 76, chooses to offer a dual basis: a subjective criterion, consisting in the intent of the State to give binding effect to the unilateral act, and an objective criterion, which is based on the protection of legitimate confidence (good faith); in another example from Spanish legal literature, Zafra Espinosa de los Monteros, Aproximación a una teoría de los actos unilaterales de los Estados, pp. 54–56, opts to follow closely the view expressed by ICJ in the Nuclear Tests cases and makes good faith and mutual trust the basis of the binding character.

189 An attempt was made to base the binding nature of unilateral acts on a rule such as acta sunt servanda or declaratio est servanda, but that solution met with many criticisms. Some members of the Commission went so far as to say that “there was no need to invent any special rule such as declaratio est servanda ... The principle of good faith was enough” (view of Mr. Lukashuk, Yearbook ... 1998, vol. I, 2524th meeting, p. 37, para. 47).

190 I.C.J. Reports 1974 (see footnote 139 above), p. 268, para. 46.191 Yearbook … 2000 (see footnote 50 above), p. 252, paras. 35–36.192 In this regard, see Higgins, Problems and Process: International

Law and How We Use It, p. 35; see also Bondía García, op. cit., pp. 76–77.

193 Turning once again to Nuclear Tests (Australia v. France), for example, the following is found: “[I]n whatever form these statements were expressed, they must be held to constitute an engagement of the State, having regard to their intention and to the circumstances in which they were made” (I.C.J. Reports 1974 (see footnote 139 above), p. 269, para. 49).


statement] as well as the circumstances in which it was made” (in other words, its context); the Court goes on to say that “a statement of this kind can create legal obliga-tions only if it is made in clear and specific terms”.194

156. In the light of the foregoing, a guiding principle could be framed concerning the basis for the binding nature of unilateral acts, worded as follows:195

“Principle 10. Basis for the binding nature of unilateral acts

“The binding nature of the unilateral acts of States is based on the principle of good faith and the intent to be bound of the State that formulated the act.”

D. Interpretation of unilateral acts

157. Given the nature of unilateral acts, to formulate rules of interpretation for them similar to those already existing for treaties proves practically impossible. In both the fourth and the fifth reports196 presented to the Com-mission, a few preliminary criteria were formulated to offer some guidelines for the interpretation of unilateral acts. The diverse views expressed by Commission mem-bers illustrated clearly the many difficulties involved in arriving at generally acceptable criteria for interpreting unilateral acts.197 Some of the suggestions of the Special Rapporteur in the above-mentioned reports, such as a ref-erence to recourse to the preparatory work, preambles or annexes, which are useful in connection with international treaties, had to be abandoned, because they did not find

194 I.C.J. Reports 2006 (see footnote 40 above), p. 28, paras. 49–50.195 The numerical placement of this draft guiding principle was

changed because the Special Rapporteur feels that the proposed principles outlined in chapter I of this report, on the grounds for invalidity and termination of unilateral acts, should be presented first, before this guiding principle, as can be seen in the annex, where all the principles are laid out in consecutive order.

196 In this regard, see Yearbook … 2001 (footnote 31 above), pp. 128–136, paras. 101–154, and Yearbook … 2002, vol. II (Part One), document A/CN.4/525 and Add.1–2, paras. 120–135, where a general rule of interpretation and some supplementary means of interpretation were put forward.

197 See Yearbook … 2001, vol. II (Part Two), in particular pp. 204–205, paras. 239–244. At that time it was felt to be premature to deal with the issue of interpretation; some members felt that the provisions of the 1969 Vienna Convention could be helpful, while others expressed just the opposite view, given the unique nature of unilateral acts. The notions of object and purpose and of the context of a unilateral act were stressed during that session of the Commission.

favour with the majority of the Commission members198 or of the authors of the legal literature.199

158. The Special Rapporteur should point out that the unilateral statements considered by ICJ, whether or not they were formulated in the context of a treaty relation-ship, were subject to interpretation, so that it is appropri-ate to mention them at this point. The Court concluded that a restrictive interpretation was called for when States made statements by which their freedom of action was to be limited, and it stressed the need to consider the circum-stances in which such a unilateral act was formulated, as well as the clarity and precision of its terms, as mentioned earlier.200

159. All the above elements may be used to interpret a unilateral act; in this sphere context plays a key role and must be given considerable weight when assessing a uni-lateral act and deducing the possible legal consequences deriving from it.

160. Following that line of thought, the Special Rappor-teur arrives at the following draft guiding principle:

“Principle 11. Interpretation of unilateral acts

“The context in which a unilateral act was formulated by a State, together with the clarity and precision of its terms, shall be given weight in interpreting it.”

161. The Special Rapporteur believes that he has ful-filled the task entrusted to him by the Commission by presenting the draft guiding principles, duly supported by reasoning, applicable to unilateral acts of States. If the Commission thinks it is appropriate, the draft principles could be referred to the Working Group on unilateral acts of States and at a later stage to the Drafting Committee for consideration. The Special Rapporteur feels that the guiding principles could be useful to States in assessing in practice the effects that might be produced by unilateral acts of States, a topic that the Commission has been con-sidering since 1997.

198 See Yearbook … 2002, vol. II (Part Two), p. 86, paras. 405–406.199 See d’Aspremont Lynden, “Les travaux de la Commission du

droit international relatifs aux actes unilatéraux des États”, pp. 180–181, devoted in particular to the interpretation of unilateral acts.

200 See I.C.J. Reports 1974 (footnote 139 above), p. 267, para. 44, and I.C.J. Reports 2006 (footnote 40 above), p. 28, paras. 49–50.


Annex

DRAFT GUIDING PRINCIPLES

In order to provide the Commission with an overview of the various draft guiding principles submitted for its consideration during this session, they are all presented below in order in a systematic fashion.

Principle 1.* Definition of a unilateral act

A unilateral act of a State means a unilateral declara-tion formulated by a State with the intent of producing certain legal effects under international law.

Addressees of unilateral acts of States

Option A

A unilateral act may be addressed to one or more States, the international community as a whole, one or more international organizations or any other entity sub-ject to international law.

Option B

A unilateral act formulated in accordance with inter-national law will produce legal effects, regardless of to whom it was addressed.

Principle 2. Capacity of States to formulate unilateral acts

Every State possesses capacity to formulate unilateral acts in accordance with international law.

Principle 3. Competence to formulate unilateral acts on behalf of the State

1. By virtue of their office, Heads of State, Heads of Government and ministers for foreign affairs are consid-ered to represent their State and to have the capacity to formulate unilateral acts on its behalf.

2. In addition to the persons mentioned in the pre-vious paragraph, other persons may be considered able to formulate unilateral acts on behalf of the State if that may be inferred from the practice followed in that regard by the formulating State and from the circumstances in which the act was formulated.

Principle 4. Subsequent confirmation of an act formulated by a person without authorization (or not qualified to do so)

A unilateral act formulated by a person not authorized (or qualified) to act on behalf of the State, in accordance with the previous guiding principles, may be confirmed subsequently by the State either expressly or through conclusive acts from which such confirmation can be clearly inferred.

Principle 5. Invalidity of an act formulated by a person not qualified to do so

A unilateral act formulated by a person not authorized or qualified to do so may be declared invalid, without

prejudice to the possibility that the State from which the act was issued may confirm it in accordance with guiding principle 4.

Principle 6. Invalidity of a unilateral act that conflicts with a norm of fundamental importance to the domestic law of the State formulating it

A State that has formulated a unilateral act may not invoke as grounds for invalidity the fact that the act con-flicts with its domestic law, unless it conflicts with a norm of fundamental importance to its domestic law and the contradiction is manifest.

Principle 7. Invalidity of unilateral acts

1. (a) A State that is the author of a unilateral act may not invoke error as grounds for declaring the act invalid, unless the act was formulated on the basis of an error of fact or a situation that was assumed by the State to exist at the time when the act was formulated and that fact or that situation formed an essential basis of its consent to be bound by the unilateral act;

(b) The foregoing shall not apply if the author State contributed by its own conduct to the error or if the cir-cumstances were such as to put that State on notice of the possibility of such an error.

2. Fraud may be invoked as grounds for declaring a unilateral act invalid if the author State was induced to formulate the act by the fraudulent conduct of another State.

3. Corruption of the representative of the State may be invoked as grounds for declaring a unilateral act inva-lid if the act was formulated owing to the corruption of the person formulating it.

4. Coercion of the person who formulated a unilat-eral act may be invoked as grounds for declaring its inva-lidity if that person formulated it as a result of acts or threats directed against him or her.

5. Any unilateral act formulated as a result of the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations is invalid.

6. Any unilateral act which at the time of its formula-tion is contrary to (or conflicts with) a peremptory norm of general international law (jus cogens) is invalid.

Principle 8. Termination of unilateral acts

A unilateral act may be terminated or revoked by the formulating State:

(a) If a specific time limit for termination of the act was set at the time of its formulation (or if termination was implicit following the performance of one or more acts);

* Contains two potential paragraphs: one relating to the definition itself and another concerning the addressees of the unilateral act.


(b) If the act was subject to a resolutive condition at the time of its formulation;

(c) If the subject matter of the unilateral act has ceased to exist;

(d) If there has been a fundamental change in the circumstances that prompted the formulation of the act (rebus sic stantibus) which renders its fulfilment impossible;

(e) If a peremptory norm of international law has emerged following its formulation which conflicts with the act.

Principle 9. Suspension of unilateral acts

A unilateral act may be suspended by the formulating State:

(a) If a circumstance that would allow for its suspen-sion was specified at the time of its formulation;

(b) If the act was subject to a suspensive condition at the time of its formulation;

(c) If its subject matter has temporarily ceased to exist;

(d) If there has been a fundamental change in the circumstances that prompted the formulation of the act which temporarily renders its fulfilment impossible.

Principle 10. Basis for the binding nature of unilateral acts

The binding nature of the unilateral acts of States is based on the principle of good faith and the intent to be bound of the State that formulated the act.

Principle 11. Interpretation of unilateral acts

The context in which a unilateral act was formulated by a State, together with the clarity and precision of its terms, shall be given weight in interpreting it.